From jep200404 at columbus.rr.com  Wed Dec  4 19:16:03 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Wed, 4 Dec 2013 13:16:03 -0500
Subject: [CentralOH] COLUG Meeting Tonight About Robot That Uses Python
In-Reply-To: <CALxu18LSqQWE=8sdzdFeYy9vvE+u32V0_BaM=n8ZM6AC0fr5Tw@mail.gmail.com>
References: <CALxu18LSqQWE=8sdzdFeYy9vvE+u32V0_BaM=n8ZM6AC0fr5Tw@mail.gmail.com>
Message-ID: <20131204131603.44fa301f.jep200404@columbus.rr.com>

COLUG Meeting Tonight About Robot That Uses Python

On Tue, 19 Nov 2013 13:17:17 -0500, Scott Merrill 
<skippy at skippy.net> wrote to COLUG's mailing list: 

> Our own Ethan Dicks will introduce us to Tourbot: Telepresence with Open Source.
> 
> Based on RUDEBOT, a Canadian conference-room robot project, Tourbot combines
> Python, pygame, Arduino, and Linux into a mobile telepresence platform. 

See colug.net for details. 


From brian.costlow at gmail.com  Thu Dec  5 02:03:39 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Wed, 4 Dec 2013 20:03:39 -0500
Subject: [CentralOH] Reminder: COhPy for December is next Monday!
Message-ID: <CACLJ_dF_YYcMeMqQ51A2G7FOiK8nW3=_UdebX-SzeN6QDM_vWw@mail.gmail.com>

Just a friendly reminder that COhPy is meeting on December 9th this month,
instead of the last Monday.

Details are here:
http://www.meetup.com/Central-Ohio-Python-Users-Group/events/149516962/

Please RSVP at Meetup.com if you plan to attend so we can plan for pizza.

Thanks!

Brian
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From jep200404 at columbus.rr.com  Fri Dec  6 00:00:12 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Thu, 5 Dec 2013 18:00:12 -0500
Subject: [CentralOH] =?utf-8?q?2013-11-29_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8=?=
Message-ID: <20131205180012.0e58d0ec.jep200404@columbus.rr.com>

Beverage for Pythonistas
http://www.blacksheepbrewery.com/beers/holy_grail_bottled_beer

gevent 1.0 released
http://blog.gevent.org/2013/11/26/gevent-1-0-released/
???
http://bash.cumulonim.biz/BashPitfalls.html
wp:EdX

wp:Windows PowerShell
permmod heck
https://www.django-cms.org/en/blog/2012/10/03/the-future-moderator/

http://www.richarddawkins.net/foundation_articles/2013/11/27/top-10-questions-from-richard-s-live-chat-on-reddit
wp:Richard Dawkins
wp:Wendy Wright
https://duckduckgo.com/html/?q=stephen+hawking+wendy+wright

Name of benzene is not after Benz of Mercedes Benz
wp:Benzene
In 1833, Eilhard Mitscherlich produced it via the distillation of benzoic acid
(from gum benzoin) and lime. He gave the compound the name benzin.
http://upload.wikimedia.org/wikipedia/commons/1/15/C-141_Starlifter_with_penguins.jpg
http://en.wikipedia.org/wiki/Sweet_Baby_James
Red Revenge by ramyb
Mort-vivant by Radscoolian
Seems Fishy... by Radcoolian
Monty Python's Holy Gr^H^Hail

some non Asian Lee's

    wp:Robert E. Lee
    wp:Vivien Leigh
    wp:Spike Lee
    wp:Bill Lee (musician)
    wp:Brenda Lee
    wp:Charles Lee (general)
    wp:Christopher Lee
    wp:David Lee (physicist)
    wp:Dorothy Lee (actress)
    wp:Edwin Gray Lee
    wp:Fitzhugh Lee
    wp:Francis Lightfoot Lee
    wp:Francis Lee
    wp:Alvin Lee
    wp:Anna Lee
    wp:Ann Lee
    wp:Amy Lee
    wp:Amos Lee
    wp:Albert Lee
    wp:Alan Lee (footballer)
    wp:Lee Harvey Oswald

wp:Temperance movement

http://www.wctu.org/

From jep200404 at columbus.rr.com  Thu Dec  5 17:53:50 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Thu, 5 Dec 2013 11:53:50 -0500
Subject: [CentralOH] =?utf-8?q?2013-10-04_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8=?=
Message-ID: <20131205115350.194e5f35.jep200404@columbus.rr.com>

    http://www.meetup.com/girldevelopitcbus/
    http://www.meetup.com/girldevelopitcbus/events/142740512/

    Tommy Emmanuel
        wp:The_Day_Finger_Pickers_Took_Over_The_World
        wp:Fur_Peace_Ranch
        with Jorma Kaukonen https://www.youtube.com/watch?v=Ugq13M21Bxw
        Tommy Emmanuel performed two sold out nights at Jorma's Fur Peace Ranch
        during the 2012 season! Jorma came out on Saturday to join Tommy! This
        is one of the few songs they played together!
        http://www.scottyhallphotography.com
        http://www.furpeaceranch.com
        wp:Jorma_Kaukonen

----

        valves for car and many bicycle tires are same
        wp:Schrader_valve

shekinah festival
pawpaw festival
ohio linux festival
game dev conference

euler #80 11.7 ms

wp:Yo_La_Tengo
wp:Ira_Kaplan
wp:Georgia_Hubley
wp:James_McNew

Use low beams in fog. Do _not_ use high beams in fog.

    #5 in http://www.wikihow.com/Drive-Safely-in-Fog
    http://www.autoinsurancequotes.com/news/headlights

----

    avant-garde music
        Laurie Anderson
            soft: Mister Heartbreak
            hard: Big Science
        The Art of Noise
            In Visible Silence
    wp:Home_of_the_Brave_(1986_film)
    shibboleth
    musicians earplugs

http://docs.python.org/2/library/sys.html
SO/IEC 9899:1999. ?Programming languages ? C.?
A public draft of this standard is available at 
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf

Learning Python is excellent
http://shop.oreilly.com/product/9781565924642.do

Columbus Python Workshop for women and their friends
http://www.meetup.com/Central-Ohio-Python-Users-Group/events/135566022/

%r for repr()
http://docs.python.org/2/library/stdtypes.html#string-formatting-operations

wp:Leo Kottke
wp:Mel Bay
Vaseline Machine Gun

repr() versus str()
sys.argv
http://docs.python.org/2/library/sys.html#sys.argv

wp:The_Unix_Programming_Environment by Kernighan & Pike
wp:C_(programming_language)
New and Old Testaments

emacs versus vi(m)

wp:Pop_Pop

http://english.chosun.com/site/data/html_dir/2013/09/14/2013091400409.html

http://www.dispatch.com/content/stories/local/2013/04/28/28-two-dead-in-hocking-hills.html


From looiebwv at gmail.com  Sun Dec  8 17:09:37 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Sun, 8 Dec 2013 11:09:37 -0500
Subject: [CentralOH] (no subject)
Message-ID: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>

Hi folks @central oh/python:



As a recent subscriber, I received notice of your Dec 9 meeting from Brian.
As I am working on a program to go along with a recently filed patent, and
am totally new to Python, I sent him a proposed ?subroutine?.  This is used
repetitively within the program.  Since I sent it to Brian, I have done
some more research and have come up with a better version as follows:



num = 1.2346

a = num(-1)

b = num(-2)

if a >7:

     a = 0

     b+ =1

elif a<3:

     a = 0

else:

      a = 5



As each stepper motor step equals .0005? of movement, with the above I can
get .0002? absolute positional accuracy with a .0005? control increment. I
have looked at some of the Python ?round? statements and examples and don?t
fully understand them so as an ?ole? retired engunear, (does 93 qualify me)
I thunk up my own way of doing things.  Maybe some of you young ones can
teach an ole man how to do things better.



This routine also has application in several other projects I have under
consideration. Would something like this, if it works, be a Python library
item?



If any of you can ?tweek? the above into working order I would appreciate
it.  I do have some other questions for you.  What do I need to buy to get
started with RPi?  I will be using my Apple computer.



Thank you for any comments you might have.  Lou Bigdan
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From andrewcfitzgerald at gmail.com  Sun Dec  8 17:34:57 2013
From: andrewcfitzgerald at gmail.com (Andrew Fitzgerald)
Date: Sun, 8 Dec 2013 11:34:57 -0500
Subject: [CentralOH] (no subject)
In-Reply-To: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
Message-ID: <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>

Hi Lou,

Could you perhaps provide a summary of what that code is supposed to do?

Right now you're assigning num the numeric value 1.2346 on the first line.

You're then attempting to call num as a function on the next 2 lines.

This won't work because num hasn't been defined as a function anywhere, and
if it was the function is overwritten by the value 1.2346 on the first line.


The part below that (if/else) looks like it should work if a and b are
assigned numeric values.

-Andrew Fitzgerald


On Sun, Dec 8, 2013 at 11:09 AM, Louis Bogdan <looiebwv at gmail.com> wrote:

> Hi folks @central oh/python:
>
>
>
> As a recent subscriber, I received notice of your Dec 9 meeting from Brian.
> As I am working on a program to go along with a recently filed patent, and
> am totally new to Python, I sent him a proposed ?subroutine?.  This is
> used repetitively within the program.  Since I sent it to Brian, I have
> done some more research and have come up with a better version as follows:
>
>
>
> num = 1.2346
>
> a = num(-1)
>
> b = num(-2)
>
> if a >7:
>
>      a = 0
>
>      b+ =1
>
> elif a<3:
>
>      a = 0
>
> else:
>
>       a = 5
>
>
>
> As each stepper motor step equals .0005? of movement, with the above I can
> get .0002? absolute positional accuracy with a .0005? control increment. I
> have looked at some of the Python ?round? statements and examples and don?t
> fully understand them so as an ?ole? retired engunear, (does 93 qualify me)
> I thunk up my own way of doing things.  Maybe some of you young ones can
> teach an ole man how to do things better.
>
>
>
> This routine also has application in several other projects I have under
> consideration. Would something like this, if it works, be a Python library
> item?
>
>
>
> If any of you can ?tweek? the above into working order I would appreciate
> it.  I do have some other questions for you.  What do I need to buy to
> get started with RPi?  I will be using my Apple computer.
>
>
>
> Thank you for any comments you might have.  Lou Bigdan
>
>
>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From looiebwv at gmail.com  Sun Dec  8 20:36:01 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Sun, 8 Dec 2013 14:36:01 -0500
Subject: [CentralOH] (no subject)
In-Reply-To: <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
Message-ID: <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>

I will start out by saying,"Have you heard that a LITTLE bit of knowledge
is a dangerous thing?"  Well, I am the Poster Boy for that saying.

num is calculated value 1.2346
a=num(-1) is indicating the numeral "6" with negative indexing notation.
b=num(-2) is indicating the numeral "4"   "         "
"              ".

if numeral "6" is greater than "7" make numeral "6" a "0" and increment the
"4" to "5".
elif numeral "6" is less than"3", meaning a "0", "1", or "2", make it a "0".
else none of the above conditions apply, make numeral "6" a "5".

EXAMPLE: 1.2340, 1.2341, 1.2342 become 1.2340
                   1.2348, 1.2349 become 1.2350
                   1.2343, 1/2344, 1.2345, 1.2346. 1.2347 become 1.2345.

So with the "Bogdan" rounding, I am never more than .0002" off calculated
position.
I then divide the modified num 1.2345 by .0005 and get 2469 which is the
number of steps required of the stepper motor to provide a movement of
1.2345" (-.0001" from theoretical.)

I hope that explains MY way of talking to a computer.  How would you talk
to Python and say the same thing and Python says,"MAN, I know what you
want!?  Lou


On Sun, Dec 8, 2013 at 11:34 AM, Andrew Fitzgerald <
andrewcfitzgerald at gmail.com> wrote:

> Hi Lou,
>
> Could you perhaps provide a summary of what that code is supposed to do?
>
> Right now you're assigning num the numeric value 1.2346 on the first line.
>
> You're then attempting to call num as a function on the next 2 lines.
>
> This won't work because num hasn't been defined as a function anywhere,
> and if it was the function is overwritten by the value 1.2346 on the first
> line.
>
>
> The part below that (if/else) looks like it should work if a and b are
> assigned numeric values.
>
> -Andrew Fitzgerald
>
>
> On Sun, Dec 8, 2013 at 11:09 AM, Louis Bogdan <looiebwv at gmail.com> wrote:
>
>>  Hi folks @central oh/python:
>>
>>
>>
>> As a recent subscriber, I received notice of your Dec 9 meeting from
>> Brian.  As I am working on a program to go along with a recently filed
>> patent, and am totally new to Python, I sent him a proposed ?subroutine?.
>> This is used repetitively within the program.  Since I sent it to Brian,
>> I have done some more research and have come up with a better version as
>> follows:
>>
>>
>>
>> num = 1.2346
>>
>> a = num(-1)
>>
>> b = num(-2)
>>
>> if a >7:
>>
>>      a = 0
>>
>>      b+ =1
>>
>> elif a<3:
>>
>>      a = 0
>>
>> else:
>>
>>       a = 5
>>
>>
>>
>> As each stepper motor step equals .0005? of movement, with the above I
>> can get .0002? absolute positional accuracy with a .0005? control
>> increment. I have looked at some of the Python ?round? statements and
>> examples and don?t fully understand them so as an ?ole? retired engunear,
>> (does 93 qualify me) I thunk up my own way of doing things.  Maybe some
>> of you young ones can teach an ole man how to do things better.
>>
>>
>>
>> This routine also has application in several other projects I have under
>> consideration. Would something like this, if it works, be a Python library
>> item?
>>
>>
>>
>> If any of you can ?tweek? the above into working order I would appreciate
>> it.  I do have some other questions for you.  What do I need to buy to
>> get started with RPi?  I will be using my Apple computer.
>>
>>
>>
>> Thank you for any comments you might have.  Lou Bigdan
>>
>>
>>
>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From jep200404 at columbus.rr.com  Sun Dec  8 20:36:08 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sun, 8 Dec 2013 14:36:08 -0500
Subject: [CentralOH] Refactoring Motor Control Code?
In-Reply-To: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
Message-ID: <20131208143608.0a10b8d7.jep200404@columbus.rr.com>

On Sun, 8 Dec 2013 11:09:37 -0500, Louis Bogdan <looiebwv at gmail.com> wrote:

> As I ... am totally new to Python ...

Come to the dojos. They are good for beginners (and others also).
We can explore really bad ways and some OK ways to do things. 
Download big files before coming. 

> ... proposed ?subroutine? ...

What you have is not a subroutine (which would be called a 
"function" in Python), but could become one. 

> num = 1.2346
> 
> a = num(-1)
> 
> b = num(-2)

I concur with Fitzgerald. 

> if a >7:
> 
>      a = 0
> 
>      b+ =1
> 
> elif a<3:
> 
>      a = 0
> 
> else:
> 
>       a = 5

goal = 5  # Unit is what?
tolerance = 2  # Unit is what?

error = a - goal
if error > +tolerance:
    a = 0
    n_too_high += 1
elif error < -tolerance:
    a = 0
else:
    a = goal

The asymmetry between a being too high or too low is curious.
Why don't you count the number of times that a is too low?

error = a - goal
if abs(error) <= tolerance:
    a = goal
else:
    a = 0
    if error > 0:
        n_too_high += 1
    else:
        n_too_low += 1

Magic numbers are evil[2]. Give them meaningful names. 

Read and follow PEP 8.[1]

Names are important. Rename b to something meaningful like 
number_of_times_too_high or n_too_high. 
Choose a better name for goal.
Document the units for each name. 

> This routine also has application in several other projects I 
> have under consideration. Would something like this, if it 
> works, be a Python library item?

What you showed is not a routine (i.e. function), but could 
become one. If you use it from many modules, then it probably 
should go into a separate module to be imported. 

> As each stepper motor step equals .0005? of movement, 
> with the above I can get .0002? absolute positional accuracy 
> with a .0005? control increment. 

It is curius that .0005" is not an even multiple 
of .0002". 
Are you microstepping the stepper motors? 
Do you have positioning feedback? 
Thermal expansion is fun.
Are you confusing accuracy with resolution? 

At least one folk who attends the dojos has experience with 
embedded programming and moving stuff. Bresenham's 
algorithm[4] is fun. 

Again, document the units for each name in the code.

> I have looked at some of the Python ?round? statements and 
> examples and don?t fully understand them ...

It helps to know what you are trying to accomplish 
before figuring out _how_ to accomplish it.

What are you trying to accomplish? 
What are the inputs?
What are the outputs?

In answering the above, try to avoid speaking in terms 
that suggest a how to accomplish whatever your goal is.

You might recognize similar statements from your career. 

Let's have some fun with bad tricky ways of doing stuff.

too_much = [0] *2
...
error = a - goal
if abs(error) <= tolerance:
    a = goal
else:
    a = 0
    #  The following is too tricky, so do not do it. 
    too_much[error < 0] += 1

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

error = a - goal

#  The following is also too tricky.
a = goal if abs(error) <= tolerance else 0

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

> What do I need to buy to get started with RPi? 

enthusiasm (Urban Meyer sells this)
Raspberry Pi B (avoid the A model)
power supply
SDHC card (get a fast one!)
A display that handles HDMI input, and HDMI cable could be helpful.
USB keyboard and USB mouse could be helpful.
Network connection could be helpful.
Go to Microcenter on Bethel.

Also read "The Zen of Python"[3].

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

n = {-1: 0, 0: 0, 1: 0}
n = dict((i, 0) for i in (-1, 0, 1))
n = dict((i-1, 0) for i in range(3))
...
#  And finally, monsieur, a wafer-thin mint.
#  It's just two wafer thin lines.
#  Just the one, sir... voila... bon app?tit...
n[min(1, max(-1, ((a - (goal - tolerance)) / (2 * tolerance + 1))))] += 1
a = goal * (not ((a - (goal - tolerance)) / (2 * tolerance + 1)))

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

[1] http://www.python.org/dev/peps/pep-0008/
[2] https://en.wikipedia.org/wiki/Magic_number_(programming)#Unnamed_numerical_constants
[3] http://www.python.org/dev/peps/pep-0020/
    Extra bonus points for reading ZMM
    https://en.wikipedia.org/wiki/Zen_and_the_Art_of_Motorcycle_Maintenance
[4] https://en.wikipedia.org/wiki/Bresenham's_line_algorithm

From jep200404 at columbus.rr.com  Sun Dec  8 20:40:10 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sun, 8 Dec 2013 14:40:10 -0500
Subject: [CentralOH] Plucking Digits From Float
In-Reply-To: <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
Message-ID: <20131208144010.16e1a950.jep200404@columbus.rr.com>

On Sun, 8 Dec 2013 14:36:01 -0500, Louis Bogdan <looiebwv at gmail.com> wrote:

> num is calculated value 1.2346
> a=num(-1) is indicating the numeral "6" with negative indexing notation.
> b=num(-2) is indicating the numeral "4"   "         "

I question the sanity of do so. Nonetheless. 

num = 1.2346
a = str(num)[-1]
b = str(num)[-2]

print num, a, b


From brian.costlow at gmail.com  Sun Dec  8 20:49:49 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Sun, 8 Dec 2013 14:49:49 -0500
Subject: [CentralOH] (no subject)
In-Reply-To: <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
Message-ID: <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>

This was my quick & dirt response to an email from Louis, and Louis reply,
which I have not digested yet. I pointed him at the list as I'm kind of
buried with some other stuff this weekend.

You get the same rounding, will take any numeric or a string representing
numeric, no float imprecision, no weird string manipulation.

>>> from decimal import Decimal as D
>>> multiplier_val = D('2000')
>>> quant_val = D('1')
>>> def custom_round(number):
...   number = D(str(number))
...   return (number * multiplier_val).quantize(quant_val) / multiplier_val

>>> custom_round(1.2340)
Decimal('1.234')
>>> custom_round(1.2341)
Decimal('1.234')
>>> custom_round(1.2342)
Decimal('1.234')
>>> custom_round(1.2343)
Decimal('1.2345')
>>> custom_round(1.2346)
Decimal('1.2345')
>>> custom_round(1.2347)
Decimal('1.2345')
>>> custom_round(1.2348)
Decimal('1.235')
>>> custom_round(1.2349)
Decimal('1.235')

  I'm so familiar with the details of my invention and its ramifications
that I didn't provide you with enough details. to explain my approach. I am
looking to make this a subroutine for the following reasons:
1. For various applications, there can be many number, N inputs.
2. For each N input, there can be as many as 30 variable incremental
modifications to N, each modification requiring that "subroutine" to make
sure that N is in suitable form for later usage.
3. The program to run this only requires the input of N and formula created
range of increments thus negating any access to N variations and increments
during  the cycle.
4. So with this "subroutine" I have .0002" absolute positional accuracy
with .0005" increment control  and other accuracies can be obtained with
positional variations.  I hope this clarifies my original email.   Lou




On Sun, Dec 8, 2013 at 2:36 PM, Louis Bogdan <looiebwv at gmail.com> wrote:

> I will start out by saying,"Have you heard that a LITTLE bit of knowledge
> is a dangerous thing?"  Well, I am the Poster Boy for that saying.
>
> num is calculated value 1.2346
> a=num(-1) is indicating the numeral "6" with negative indexing notation.
> b=num(-2) is indicating the numeral "4"   "         "
> "              ".
>
> if numeral "6" is greater than "7" make numeral "6" a "0" and increment
> the "4" to "5".
> elif numeral "6" is less than"3", meaning a "0", "1", or "2", make it a
> "0".
> else none of the above conditions apply, make numeral "6" a "5".
>
> EXAMPLE: 1.2340, 1.2341, 1.2342 become 1.2340
>                    1.2348, 1.2349 become 1.2350
>                    1.2343, 1/2344, 1.2345, 1.2346. 1.2347 become 1.2345.
>
> So with the "Bogdan" rounding, I am never more than .0002" off calculated
> position.
> I then divide the modified num 1.2345 by .0005 and get 2469 which is the
> number of steps required of the stepper motor to provide a movement of
> 1.2345" (-.0001" from theoretical.)
>
> I hope that explains MY way of talking to a computer.  How would you talk
> to Python and say the same thing and Python says,"MAN, I know what you
> want!?  Lou
>
>
> On Sun, Dec 8, 2013 at 11:34 AM, Andrew Fitzgerald <
> andrewcfitzgerald at gmail.com> wrote:
>
>> Hi Lou,
>>
>> Could you perhaps provide a summary of what that code is supposed to do?
>>
>> Right now you're assigning num the numeric value 1.2346 on the first line.
>>
>> You're then attempting to call num as a function on the next 2 lines.
>>
>> This won't work because num hasn't been defined as a function anywhere,
>> and if it was the function is overwritten by the value 1.2346 on the first
>> line.
>>
>>
>> The part below that (if/else) looks like it should work if a and b are
>> assigned numeric values.
>>
>> -Andrew Fitzgerald
>>
>>
>>  On Sun, Dec 8, 2013 at 11:09 AM, Louis Bogdan <looiebwv at gmail.com>wrote:
>>
>>>  Hi folks @central oh/python:
>>>
>>>
>>>
>>> As a recent subscriber, I received notice of your Dec 9 meeting from
>>> Brian.  As I am working on a program to go along with a recently filed
>>> patent, and am totally new to Python, I sent him a proposed ?subroutine?.
>>> This is used repetitively within the program.  Since I sent it to
>>> Brian, I have done some more research and have come up with a better
>>> version as follows:
>>>
>>>
>>>
>>> num = 1.2346
>>>
>>> a = num(-1)
>>>
>>> b = num(-2)
>>>
>>> if a >7:
>>>
>>>      a = 0
>>>
>>>      b+ =1
>>>
>>> elif a<3:
>>>
>>>      a = 0
>>>
>>> else:
>>>
>>>       a = 5
>>>
>>>
>>>
>>> As each stepper motor step equals .0005? of movement, with the above I
>>> can get .0002? absolute positional accuracy with a .0005? control
>>> increment. I have looked at some of the Python ?round? statements and
>>> examples and don?t fully understand them so as an ?ole? retired engunear,
>>> (does 93 qualify me) I thunk up my own way of doing things.  Maybe some
>>> of you young ones can teach an ole man how to do things better.
>>>
>>>
>>>
>>> This routine also has application in several other projects I have under
>>> consideration. Would something like this, if it works, be a Python library
>>> item?
>>>
>>>
>>>
>>> If any of you can ?tweek? the above into working order I would
>>> appreciate it.  I do have some other questions for you.  What do I need
>>> to buy to get started with RPi?  I will be using my Apple computer.
>>>
>>>
>>>
>>> Thank you for any comments you might have.  Lou Bigdan
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> CentralOH mailing list
>>> CentralOH at python.org
>>> https://mail.python.org/mailman/listinfo/centraloh
>>>
>>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From jep200404 at columbus.rr.com  Sun Dec  8 21:00:07 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sun, 8 Dec 2013 15:00:07 -0500
Subject: [CentralOH] Say What You Want To Accomplish
In-Reply-To: <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
Message-ID: <20131208150007.42d09110.jep200404@columbus.rr.com>


On Sun, 8 Dec 2013 14:36:01 -0500, Louis Bogdan <looiebwv at gmail.com> wrote:

> if numeral "6" is greater than "7" make numeral "6" a "0" and increment the
> "4" to "5".
> elif numeral "6" is less than"3", meaning a "0", "1", or "2", make it a "0".
> else none of the above conditions apply, make numeral "6" a "5".

Uggh! 

There is a simple problem with a simple solution hiding in 
the above. 

Tell us what you want to accomplish in prose, 
without magic numbers, without suggesting implementations. 
Do not overthink it. 
Name the quantities. 
If those are not the right terms, use the right ones. 

Tell us about the hardware. 
What are its capabilities?
What are its limitations?

> if numeral "6" is greater than "7" ...

"6" is greater than "7" for sufficiently large values of "6". :-)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

step_resolution = 0.0005  # Unit is one inch.

def closest(x, resolution):
    return round(x / resolution) * resolution

for x in range(10 + 1):
    x = (12340 + x) / 10000.0
    print x, closest(x, step_resolution)


From jep200404 at columbus.rr.com  Sun Dec  8 21:09:01 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sun, 8 Dec 2013 15:09:01 -0500
Subject: [CentralOH] What is the form suitable for later use?
In-Reply-To: <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
Message-ID: <20131208150901.4a1da964.jep200404@columbus.rr.com>

On Sun, 8 Dec 2013 14:49:49 -0500, Brian Costlow <brian.costlow at gmail.com> wrote:

> ... each modification requiring that "subroutine" to make
> sure that N is in suitable form for later usage.

What is the form suitable for later use? 


From brian.costlow at gmail.com  Sun Dec  8 21:11:04 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Sun, 8 Dec 2013 15:11:04 -0500
Subject: [CentralOH] What is the form suitable for later use?
In-Reply-To: <20131208150901.4a1da964.jep200404@columbus.rr.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <20131208150901.4a1da964.jep200404@columbus.rr.com>
Message-ID: <CACLJ_dG=ECmMjtuR1zZwTTZW53iam6LZL-Oa6-3K6nOv4zm-gw@mail.gmail.com>

No idea, that part was Louis' response, but I'm guessing that he means it's
rounded as described above so it always lands on a step.


On Sun, Dec 8, 2013 at 3:09 PM, <jep200404 at columbus.rr.com> wrote:

> On Sun, 8 Dec 2013 14:49:49 -0500, Brian Costlow <brian.costlow at gmail.com>
> wrote:
>
> > ... each modification requiring that "subroutine" to make
> > sure that N is in suitable form for later usage.
>
> What is the form suitable for later use?
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
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From looiebwv at gmail.com  Sun Dec  8 22:10:09 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Sun, 8 Dec 2013 16:10:09 -0500
Subject: [CentralOH] (no subject)
In-Reply-To: <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
Message-ID: <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>

I see that there are some questions about my explanation of what I'm trying
to do.  Would it clarify things if my explanation read as follows:
num(-1) denotes right-hand most digit of num in index position notation
num(-2) denotes the 3rd position digit of num in index position notation.

I don't know how to say it in computer language, that's why I'm asking for
your help. Lou


On Sun, Dec 8, 2013 at 2:49 PM, Brian Costlow <brian.costlow at gmail.com>wrote:

> This was my quick & dirt response to an email from Louis, and Louis reply,
> which I have not digested yet. I pointed him at the list as I'm kind of
> buried with some other stuff this weekend.
>
> You get the same rounding, will take any numeric or a string representing
> numeric, no float imprecision, no weird string manipulation.
>
> >>> from decimal import Decimal as D
> >>> multiplier_val = D('2000')
> >>> quant_val = D('1')
> >>> def custom_round(number):
> ...   number = D(str(number))
> ...   return (number * multiplier_val).quantize(quant_val) / multiplier_val
>
> >>> custom_round(1.2340)
> Decimal('1.234')
> >>> custom_round(1.2341)
> Decimal('1.234')
> >>> custom_round(1.2342)
> Decimal('1.234')
> >>> custom_round(1.2343)
> Decimal('1.2345')
> >>> custom_round(1.2346)
> Decimal('1.2345')
> >>> custom_round(1.2347)
> Decimal('1.2345')
> >>> custom_round(1.2348)
> Decimal('1.235')
> >>> custom_round(1.2349)
> Decimal('1.235')
>
>   I'm so familiar with the details of my invention and its ramifications
> that I didn't provide you with enough details. to explain my approach. I am
> looking to make this a subroutine for the following reasons:
> 1. For various applications, there can be many number, N inputs.
> 2. For each N input, there can be as many as 30 variable incremental
> modifications to N, each modification requiring that "subroutine" to make
> sure that N is in suitable form for later usage.
> 3. The program to run this only requires the input of N and formula
> created range of increments thus negating any access to N variations and
> increments during  the cycle.
> 4. So with this "subroutine" I have .0002" absolute positional accuracy
> with .0005" increment control  and other accuracies can be obtained with
> positional variations.  I hope this clarifies my original email.   Lou
>
>
>
>
> On Sun, Dec 8, 2013 at 2:36 PM, Louis Bogdan <looiebwv at gmail.com> wrote:
>
>> I will start out by saying,"Have you heard that a LITTLE bit of knowledge
>> is a dangerous thing?"  Well, I am the Poster Boy for that saying.
>>
>> num is calculated value 1.2346
>> a=num(-1) is indicating the numeral "6" with negative indexing notation.
>> b=num(-2) is indicating the numeral "4"   "         "
>> "              ".
>>
>> if numeral "6" is greater than "7" make numeral "6" a "0" and increment
>> the "4" to "5".
>> elif numeral "6" is less than"3", meaning a "0", "1", or "2", make it a
>> "0".
>> else none of the above conditions apply, make numeral "6" a "5".
>>
>> EXAMPLE: 1.2340, 1.2341, 1.2342 become 1.2340
>>                    1.2348, 1.2349 become 1.2350
>>                    1.2343, 1/2344, 1.2345, 1.2346. 1.2347 become 1.2345.
>>
>> So with the "Bogdan" rounding, I am never more than .0002" off calculated
>> position.
>> I then divide the modified num 1.2345 by .0005 and get 2469 which is the
>> number of steps required of the stepper motor to provide a movement of
>> 1.2345" (-.0001" from theoretical.)
>>
>> I hope that explains MY way of talking to a computer.  How would you talk
>> to Python and say the same thing and Python says,"MAN, I know what you
>> want!?  Lou
>>
>>
>> On Sun, Dec 8, 2013 at 11:34 AM, Andrew Fitzgerald <
>> andrewcfitzgerald at gmail.com> wrote:
>>
>>> Hi Lou,
>>>
>>> Could you perhaps provide a summary of what that code is supposed to do?
>>>
>>> Right now you're assigning num the numeric value 1.2346 on the first
>>> line.
>>>
>>> You're then attempting to call num as a function on the next 2 lines.
>>>
>>> This won't work because num hasn't been defined as a function anywhere,
>>> and if it was the function is overwritten by the value 1.2346 on the first
>>> line.
>>>
>>>
>>> The part below that (if/else) looks like it should work if a and b are
>>> assigned numeric values.
>>>
>>> -Andrew Fitzgerald
>>>
>>>
>>>  On Sun, Dec 8, 2013 at 11:09 AM, Louis Bogdan <looiebwv at gmail.com>wrote:
>>>
>>>>  Hi folks @central oh/python:
>>>>
>>>>
>>>>
>>>> As a recent subscriber, I received notice of your Dec 9 meeting from
>>>> Brian.  As I am working on a program to go along with a recently filed
>>>> patent, and am totally new to Python, I sent him a proposed ?subroutine?.
>>>> This is used repetitively within the program.  Since I sent it to
>>>> Brian, I have done some more research and have come up with a better
>>>> version as follows:
>>>>
>>>>
>>>>
>>>> num = 1.2346
>>>>
>>>> a = num(-1)
>>>>
>>>> b = num(-2)
>>>>
>>>> if a >7:
>>>>
>>>>      a = 0
>>>>
>>>>      b+ =1
>>>>
>>>> elif a<3:
>>>>
>>>>      a = 0
>>>>
>>>> else:
>>>>
>>>>       a = 5
>>>>
>>>>
>>>>
>>>> As each stepper motor step equals .0005? of movement, with the above I
>>>> can get .0002? absolute positional accuracy with a .0005? control
>>>> increment. I have looked at some of the Python ?round? statements and
>>>> examples and don?t fully understand them so as an ?ole? retired engunear,
>>>> (does 93 qualify me) I thunk up my own way of doing things.  Maybe
>>>> some of you young ones can teach an ole man how to do things better.
>>>>
>>>>
>>>>
>>>> This routine also has application in several other projects I have
>>>> under consideration. Would something like this, if it works, be a Python
>>>> library item?
>>>>
>>>>
>>>>
>>>> If any of you can ?tweek? the above into working order I would
>>>> appreciate it.  I do have some other questions for you.  What do I
>>>> need to buy to get started with RPi?  I will be using my Apple
>>>> computer.
>>>>
>>>>
>>>>
>>>> Thank you for any comments you might have.  Lou Bigdan
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> CentralOH mailing list
>>>> CentralOH at python.org
>>>> https://mail.python.org/mailman/listinfo/centraloh
>>>>
>>>>
>>>
>>> _______________________________________________
>>> CentralOH mailing list
>>> CentralOH at python.org
>>> https://mail.python.org/mailman/listinfo/centraloh
>>>
>>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From jep200404 at columbus.rr.com  Sun Dec  8 23:06:01 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sun, 8 Dec 2013 17:06:01 -0500
Subject: [CentralOH] State The Problem Simply
In-Reply-To: <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
Message-ID: <20131208170601.52548c40.jep200404@columbus.rr.com>

State your problem simply.

On Sun, 8 Dec 2013 16:10:09 -0500, Louis Bogdan <looiebwv at gmail.com> wrote:

> I see that there are some questions about my explanation of what I'm trying
> to do.  Would it clarify things if my explanation read as follows:
> num(-1) denotes right-hand most digit of num in index position notation
> num(-2) denotes the 3rd position digit of num in index position notation.

I understand your notation. 
All the talk about picking out digits and doing things depending 
on which digit has which value is an awkward way of stating your 
problem.

> I don't know how to say it in computer language, ... 

So say it in engunearing English. 

The following is an example of how to simply state a problem. 

    I have stepper motors with a given resolution. 

    For a given absolute position and stepper motor resolution, 
    I want to calculate the number of absolute 
    steps that is closest to the given absolute position. 

    How would I do that in Python? 

The above is just an example of how to state a problem simply. 
The problem stated above is different that your problem. 

State your problem so simply. 

I could have made the statement complicated by mentioning a 
particular resolution and what to do based on which digit has 
which value. That would just obscure the problem. 

































































A solution to the above problem might be something like: 

def foo(d, steps_per_unit):
    '''Returns number of stepper motor steps
    closest to given distance d,
    for stepper motor step resolution steps_per_unit.

    Unit in steps_per_unit must be same as unit of d.'''

    return int(round(d * steps_per_unit))

MOTOR_STEP_RATE = 2000  #  Unit is 1 step/inch.

foo(1.23456, MOTOR_STEP_RATE)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

A solution to the another problem might be something like: 

def goo(d, steps_per_unit):
    '''Returns closest distance to d that a 
    steps_per_unit stepper motor can achieve. 

    Unit in steps_per_unit must be same as unit of d.'''
    return round(d * steps_per_unit) / steps_per_unit

MOTOR_STEP_RATE = 2000  #  Unit is 1 step/inch.

goo(1.23456, MOTOR_STEP_RATE)


From jep200404 at columbus.rr.com  Sun Dec  8 23:12:24 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sun, 8 Dec 2013 17:12:24 -0500
Subject: [CentralOH] =?utf-8?q?2013-12-06_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8=?=
Message-ID: <20131208171224.6e6122cb.jep200404@columbus.rr.com>

Solved a messy Python package/virtualenv problem. 

Python T-shirt:
The House Always Wins
by Wenceslao Almazan
wenceslaoalmazan.com
shirt.woot.com/offers/the-house-always-wins

aromaku indonesian food truck recommended by
facebook.com/ar0maku
https://twitter.com/Ar0maku

pdfa/Wes McKinney/pandas

Try to install most Python packages within a virtual environment with pip.
Install the barest minimum of Python packages with the system package manager.

Had much trouble with python packages in Linux Mint 15 MATE 32-bit
New virtual environments inherited all packages from system, 
even with --no-site-packages.
Could _not_ avoid inheriting system Python packages.
Linux Mint installs many Python packages.

Someone did a clean install of the Linux above,
and found that installing pip by installing virtualenv, 
seemed to solve the problem. See the attached tarball.
Compare requirements.20131207-1630-initial
with foo/requirements.20131207-1633-initial.
Follow installation in "installation" file.

The linuxmint-15-mate-dvd-32bit-20131207-1454-after-install-before-update
file might be helpful for restoring the messed up system.
Look at output of diff between above file and current list 
of installed system packages. 

Pup In Training
by fablefire
shirt.woot.com/offers/pup-in-training

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From jep200404 at columbus.rr.com  Mon Dec  9 15:24:20 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Mon, 9 Dec 2013 09:24:20 -0500
Subject: [CentralOH] Meeting Reminder
Message-ID: <20131209092420.0f76fb0e.jep200404@columbus.rr.com>

Meeting tonight
Eric Floehr will be giving a talk on computer vision in Python.
http://www.meetup.com/Central-Ohio-Python-Users-Group/events/149516962/

The Explorers Club at 1586 South High Street is open until 10pm, 
so is a candidate for after the meeting.
http://www.explorersclubmv.com/


From joe at joeshaw.org  Mon Dec  9 15:57:31 2013
From: joe at joeshaw.org (Joe Shaw)
Date: Mon, 9 Dec 2013 09:57:31 -0500
Subject: [CentralOH] Plucking Digits From Float
In-Reply-To: <20131208144010.16e1a950.jep200404@columbus.rr.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <20131208144010.16e1a950.jep200404@columbus.rr.com>
Message-ID: <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>

Hi,

It's worth pointing out also that floating point values are an
approximation.  This is one reason why you should never do direct
comparisons with floating point numbers, but it could also bite you
here.  It's possible that 1.2346 (or any value you choose) cannot be
precisely represented as you wish, and so converting it to a string
and taking the negative index might be very, very wrong.

0.1 is one such number, and it can be demonstrated in python on some
platforms.  Go into the Python REPL and type "0.1" and you might get
"0.10000000000000001" back.

If this is really important you can store your values as integers --
which are exactly precise -- and handle the decimals yourself.  (In
other words, your own implemention of fixed point values.)

Joe

On Sun, Dec 8, 2013 at 2:40 PM,  <jep200404 at columbus.rr.com> wrote:
> On Sun, 8 Dec 2013 14:36:01 -0500, Louis Bogdan <looiebwv at gmail.com> wrote:
>
>> num is calculated value 1.2346
>> a=num(-1) is indicating the numeral "6" with negative indexing notation.
>> b=num(-2) is indicating the numeral "4"   "         "
>
> I question the sanity of do so. Nonetheless.
>
> num = 1.2346
> a = str(num)[-1]
> b = str(num)[-2]
>
> print num, a, b
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh

From brian.costlow at gmail.com  Mon Dec  9 16:21:07 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Mon, 9 Dec 2013 10:21:07 -0500
Subject: [CentralOH] Plucking Digits From Float
In-Reply-To: <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <20131208144010.16e1a950.jep200404@columbus.rr.com>
 <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>
Message-ID: <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>

There is an existing Decimal library in the standard library, which can be
used for a lot of this kind of work. It's designed to avoid these kind of
issues (mostly).

http://docs.python.org/2/library/decimal.html

Although since he is working with hardware, if the boundary can only pass
floats into Python, he still will have potential issues. But using Decimal
you can actually trap instances of inexact conversion and deal with them,
instead of having them sneak by.






On Mon, Dec 9, 2013 at 9:57 AM, Joe Shaw <joe at joeshaw.org> wrote:

> Hi,
>
> It's worth pointing out also that floating point values are an
> approximation.  This is one reason why you should never do direct
> comparisons with floating point numbers, but it could also bite you
> here.  It's possible that 1.2346 (or any value you choose) cannot be
> precisely represented as you wish, and so converting it to a string
> and taking the negative index might be very, very wrong.
>
> 0.1 is one such number, and it can be demonstrated in python on some
> platforms.  Go into the Python REPL and type "0.1" and you might get
> "0.10000000000000001" back.
>
> If this is really important you can store your values as integers --
> which are exactly precise -- and handle the decimals yourself.  (In
> other words, your own implemention of fixed point values.)
>
> Joe
>
> On Sun, Dec 8, 2013 at 2:40 PM,  <jep200404 at columbus.rr.com> wrote:
> > On Sun, 8 Dec 2013 14:36:01 -0500, Louis Bogdan <looiebwv at gmail.com>
> wrote:
> >
> >> num is calculated value 1.2346
> >> a=num(-1) is indicating the numeral "6" with negative indexing notation.
> >> b=num(-2) is indicating the numeral "4"   "         "
> >
> > I question the sanity of do so. Nonetheless.
> >
> > num = 1.2346
> > a = str(num)[-1]
> > b = str(num)[-2]
> >
> > print num, a, b
> >
> > _______________________________________________
> > CentralOH mailing list
> > CentralOH at python.org
> > https://mail.python.org/mailman/listinfo/centraloh
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
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From looiebwv at gmail.com  Mon Dec  9 16:32:17 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Mon, 9 Dec 2013 10:32:17 -0500
Subject: [CentralOH] Plucking Digits From Float
In-Reply-To: <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <20131208144010.16e1a950.jep200404@columbus.rr.com>
 <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>
 <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>
Message-ID: <CAChFk2Y8cUJSCLgjpvETXQpsVu0kjqgESf4SbvHX2=OrzXmwHA@mail.gmail.com>

If my number 1.2346 was 12346.0, could I still do what I do in my proposed
function?  What I would be doing is multiplying everything by 10000 to
convert to integers. The end result would still be tbe same.   lou


On Mon, Dec 9, 2013 at 10:21 AM, Brian Costlow <brian.costlow at gmail.com>wrote:

> There is an existing Decimal library in the standard library, which can be
> used for a lot of this kind of work. It's designed to avoid these kind of
> issues (mostly).
>
> http://docs.python.org/2/library/decimal.html
>
> Although since he is working with hardware, if the boundary can only pass
> floats into Python, he still will have potential issues. But using Decimal
> you can actually trap instances of inexact conversion and deal with them,
> instead of having them sneak by.
>
>
>
>
>
>
> On Mon, Dec 9, 2013 at 9:57 AM, Joe Shaw <joe at joeshaw.org> wrote:
>
>> Hi,
>>
>> It's worth pointing out also that floating point values are an
>> approximation.  This is one reason why you should never do direct
>> comparisons with floating point numbers, but it could also bite you
>> here.  It's possible that 1.2346 (or any value you choose) cannot be
>> precisely represented as you wish, and so converting it to a string
>> and taking the negative index might be very, very wrong.
>>
>> 0.1 is one such number, and it can be demonstrated in python on some
>> platforms.  Go into the Python REPL and type "0.1" and you might get
>> "0.10000000000000001" back.
>>
>> If this is really important you can store your values as integers --
>> which are exactly precise -- and handle the decimals yourself.  (In
>> other words, your own implemention of fixed point values.)
>>
>> Joe
>>
>> On Sun, Dec 8, 2013 at 2:40 PM,  <jep200404 at columbus.rr.com> wrote:
>> > On Sun, 8 Dec 2013 14:36:01 -0500, Louis Bogdan <looiebwv at gmail.com>
>> wrote:
>> >
>> >> num is calculated value 1.2346
>> >> a=num(-1) is indicating the numeral "6" with negative indexing
>> notation.
>> >> b=num(-2) is indicating the numeral "4"   "         "
>> >
>> > I question the sanity of do so. Nonetheless.
>> >
>> > num = 1.2346
>> > a = str(num)[-1]
>> > b = str(num)[-2]
>> >
>> > print num, a, b
>> >
>> > _______________________________________________
>> > CentralOH mailing list
>> > CentralOH at python.org
>> > https://mail.python.org/mailman/listinfo/centraloh
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From joe at joeshaw.org  Mon Dec  9 16:35:40 2013
From: joe at joeshaw.org (Joe Shaw)
Date: Mon, 9 Dec 2013 10:35:40 -0500
Subject: [CentralOH] Plucking Digits From Float
In-Reply-To: <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <20131208144010.16e1a950.jep200404@columbus.rr.com>
 <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>
 <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>
Message-ID: <CAOxvq7ykaihW9OOrhFRHbWneOFN=+L_kZwhGqbPc9BzHo4K8ag@mail.gmail.com>

Hi,

Yep, good call.  I wasn't familiar with the Decimal library and hadn't
caught up to your other message on the thread. It definitely looks
like it'll fit the bill.

I would be a bit surprised if the hardware returned floats... most
small embedded components don't have FPUs or IEEE-754 implementations.
 (And for things like medical devices, they'd more likely use some
fixed point implementation to avoid these kinds of rounding errors.)

Joe

On Mon, Dec 9, 2013 at 10:21 AM, Brian Costlow <brian.costlow at gmail.com> wrote:
> There is an existing Decimal library in the standard library, which can be
> used for a lot of this kind of work. It's designed to avoid these kind of
> issues (mostly).
>
> http://docs.python.org/2/library/decimal.html
>
> Although since he is working with hardware, if the boundary can only pass
> floats into Python, he still will have potential issues. But using Decimal
> you can actually trap instances of inexact conversion and deal with them,
> instead of having them sneak by.
>
>
>
>
>
>
> On Mon, Dec 9, 2013 at 9:57 AM, Joe Shaw <joe at joeshaw.org> wrote:
>>
>> Hi,
>>
>> It's worth pointing out also that floating point values are an
>> approximation.  This is one reason why you should never do direct
>> comparisons with floating point numbers, but it could also bite you
>> here.  It's possible that 1.2346 (or any value you choose) cannot be
>> precisely represented as you wish, and so converting it to a string
>> and taking the negative index might be very, very wrong.
>>
>> 0.1 is one such number, and it can be demonstrated in python on some
>> platforms.  Go into the Python REPL and type "0.1" and you might get
>> "0.10000000000000001" back.
>>
>> If this is really important you can store your values as integers --
>> which are exactly precise -- and handle the decimals yourself.  (In
>> other words, your own implemention of fixed point values.)
>>
>> Joe
>>
>> On Sun, Dec 8, 2013 at 2:40 PM,  <jep200404 at columbus.rr.com> wrote:
>> > On Sun, 8 Dec 2013 14:36:01 -0500, Louis Bogdan <looiebwv at gmail.com>
>> > wrote:
>> >
>> >> num is calculated value 1.2346
>> >> a=num(-1) is indicating the numeral "6" with negative indexing
>> >> notation.
>> >> b=num(-2) is indicating the numeral "4"   "         "
>> >
>> > I question the sanity of do so. Nonetheless.
>> >
>> > num = 1.2346
>> > a = str(num)[-1]
>> > b = str(num)[-2]
>> >
>> > print num, a, b
>> >
>> > _______________________________________________
>> > CentralOH mailing list
>> > CentralOH at python.org
>> > https://mail.python.org/mailman/listinfo/centraloh
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>

From jep200404 at columbus.rr.com  Mon Dec  9 16:42:23 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Mon, 9 Dec 2013 10:42:23 -0500
Subject: [CentralOH] Define The Problem, Then Solve
In-Reply-To: <CAChFk2Y8cUJSCLgjpvETXQpsVu0kjqgESf4SbvHX2=OrzXmwHA@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <20131208144010.16e1a950.jep200404@columbus.rr.com>
 <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>
 <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>
 <CAChFk2Y8cUJSCLgjpvETXQpsVu0kjqgESf4SbvHX2=OrzXmwHA@mail.gmail.com>
Message-ID: <20131209104223.0cf0adde.jep200404@columbus.rr.com>

On Mon, 9 Dec 2013 10:32:17 -0500, Louis Bogdan <looiebwv at gmail.com> wrote:

> If ...

Come to the meeting and after-meeting. 
It will be good place to discuss and define the problem. 

Once we have a good definition of the problem, 
solving the problem should be easy.


From brian.costlow at gmail.com  Mon Dec  9 16:44:17 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Mon, 9 Dec 2013 10:44:17 -0500
Subject: [CentralOH] Plucking Digits From Float
In-Reply-To: <CAOxvq7ykaihW9OOrhFRHbWneOFN=+L_kZwhGqbPc9BzHo4K8ag@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <20131208144010.16e1a950.jep200404@columbus.rr.com>
 <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>
 <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>
 <CAOxvq7ykaihW9OOrhFRHbWneOFN=+L_kZwhGqbPc9BzHo4K8ag@mail.gmail.com>
Message-ID: <CACLJ_dETxx0xgEa1Ffo_gCUe0a0Zk+yE9pLWNjVjU3QzhSr1iA@mail.gmail.com>

The (very few) hobby things I have done return ints of some type from the
hardware, but it's not something I'm terribly familiar with.

And that was an off-the-top-of-my-head starting point. There's a couple
issues with my code, including an unnecessary str conversion and not
setting the context correctly.


On Mon, Dec 9, 2013 at 10:35 AM, Joe Shaw <joe at joeshaw.org> wrote:

> Hi,
>
> Yep, good call.  I wasn't familiar with the Decimal library and hadn't
> caught up to your other message on the thread. It definitely looks
> like it'll fit the bill.
>
> I would be a bit surprised if the hardware returned floats... most
> small embedded components don't have FPUs or IEEE-754 implementations.
>  (And for things like medical devices, they'd more likely use some
> fixed point implementation to avoid these kinds of rounding errors.)
>
> Joe
>
> On Mon, Dec 9, 2013 at 10:21 AM, Brian Costlow <brian.costlow at gmail.com>
> wrote:
> > There is an existing Decimal library in the standard library, which can
> be
> > used for a lot of this kind of work. It's designed to avoid these kind of
> > issues (mostly).
> >
> > http://docs.python.org/2/library/decimal.html
> >
> > Although since he is working with hardware, if the boundary can only pass
> > floats into Python, he still will have potential issues. But using
> Decimal
> > you can actually trap instances of inexact conversion and deal with them,
> > instead of having them sneak by.
> >
> >
> >
> >
> >
> >
> > On Mon, Dec 9, 2013 at 9:57 AM, Joe Shaw <joe at joeshaw.org> wrote:
> >>
> >> Hi,
> >>
> >> It's worth pointing out also that floating point values are an
> >> approximation.  This is one reason why you should never do direct
> >> comparisons with floating point numbers, but it could also bite you
> >> here.  It's possible that 1.2346 (or any value you choose) cannot be
> >> precisely represented as you wish, and so converting it to a string
> >> and taking the negative index might be very, very wrong.
> >>
> >> 0.1 is one such number, and it can be demonstrated in python on some
> >> platforms.  Go into the Python REPL and type "0.1" and you might get
> >> "0.10000000000000001" back.
> >>
> >> If this is really important you can store your values as integers --
> >> which are exactly precise -- and handle the decimals yourself.  (In
> >> other words, your own implemention of fixed point values.)
> >>
> >> Joe
> >>
> >> On Sun, Dec 8, 2013 at 2:40 PM,  <jep200404 at columbus.rr.com> wrote:
> >> > On Sun, 8 Dec 2013 14:36:01 -0500, Louis Bogdan <looiebwv at gmail.com>
> >> > wrote:
> >> >
> >> >> num is calculated value 1.2346
> >> >> a=num(-1) is indicating the numeral "6" with negative indexing
> >> >> notation.
> >> >> b=num(-2) is indicating the numeral "4"   "         "
> >> >
> >> > I question the sanity of do so. Nonetheless.
> >> >
> >> > num = 1.2346
> >> > a = str(num)[-1]
> >> > b = str(num)[-2]
> >> >
> >> > print num, a, b
> >> >
> >> > _______________________________________________
> >> > CentralOH mailing list
> >> > CentralOH at python.org
> >> > https://mail.python.org/mailman/listinfo/centraloh
> >> _______________________________________________
> >> CentralOH mailing list
> >> CentralOH at python.org
> >> https://mail.python.org/mailman/listinfo/centraloh
> >
> >
> >
> > _______________________________________________
> > CentralOH mailing list
> > CentralOH at python.org
> > https://mail.python.org/mailman/listinfo/centraloh
> >
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
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From jep200404 at columbus.rr.com  Mon Dec  9 16:53:00 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Mon, 9 Dec 2013 10:53:00 -0500
Subject: [CentralOH] =?utf-8?q?2013-12-06_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8gc3VkbyBhcHQtZ2V0IC15IGluc3RhbGwgcHl0aG9u?=
 =?utf-8?q?-virtualenv?=
In-Reply-To: <20131208171224.6e6122cb.jep200404@columbus.rr.com>
References: <20131208171224.6e6122cb.jep200404@columbus.rr.com>
Message-ID: <20131209105300.0088d3a0.jep200404@columbus.rr.com>

On Sun, 8 Dec 2013 17:12:24 -0500, jep200404 at columbus.rr.com wrote:

> Solved a messy Python package/virtualenv problem. 

The essence of the solution seems to have been:

    sudo apt-get -y install python-virtualenv

which was inspired by 'IPython & Notebook on Xubuntu 12.10 Desktop i386'
https://mail.python.org/pipermail/centraloh/2013-February/001544.html


From brian.costlow at gmail.com  Mon Dec  9 16:53:33 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Mon, 9 Dec 2013 10:53:33 -0500
Subject: [CentralOH] Plucking Digits From Float
In-Reply-To: <CAChFk2Y8cUJSCLgjpvETXQpsVu0kjqgESf4SbvHX2=OrzXmwHA@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <20131208144010.16e1a950.jep200404@columbus.rr.com>
 <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>
 <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>
 <CAChFk2Y8cUJSCLgjpvETXQpsVu0kjqgESf4SbvHX2=OrzXmwHA@mail.gmail.com>
Message-ID: <CACLJ_dF6fmTaAdUm0HL4VDrOX53d1EGFFWsgShtNEJUpx=TX2g@mail.gmail.com>

If you are doing string manipulation, this is where it gets tricky, and
where we are unclear what you are trying to do.

If input is 1.2346 the output is 1.2345 (from your examples)

But if the input is 12346.0, what is your expected output? Based on the
0.0005 step, I would expect it stays 12346.0

But wait, if we get 1234.6 what do we do? If we are just manipulating the
last 2 digits of a string, we end up with 1234.5

Which of those would be correct? What if it's 1234.60 in the string, which
is the same numeric value as 1234.6.

To avoid those issues, you need a bunch more string manipulation. This is
why we are asking you to step back and give a high level description of the
problem without being fixated on your algorithm.




On Mon, Dec 9, 2013 at 10:32 AM, Louis Bogdan <looiebwv at gmail.com> wrote:

> If my number 1.2346 was 12346.0, could I still do what I do in my proposed
> function?  What I would be doing is multiplying everything by 10000 to
> convert to integers. The end result would still be tbe same.   lou
>
>
> On Mon, Dec 9, 2013 at 10:21 AM, Brian Costlow <brian.costlow at gmail.com>wrote:
>
>> There is an existing Decimal library in the standard library, which can
>> be used for a lot of this kind of work. It's designed to avoid these kind
>> of issues (mostly).
>>
>> http://docs.python.org/2/library/decimal.html
>>
>> Although since he is working with hardware, if the boundary can only pass
>> floats into Python, he still will have potential issues. But using Decimal
>> you can actually trap instances of inexact conversion and deal with them,
>> instead of having them sneak by.
>>
>>
>>
>>
>>
>>
>> On Mon, Dec 9, 2013 at 9:57 AM, Joe Shaw <joe at joeshaw.org> wrote:
>>
>>> Hi,
>>>
>>> It's worth pointing out also that floating point values are an
>>> approximation.  This is one reason why you should never do direct
>>> comparisons with floating point numbers, but it could also bite you
>>> here.  It's possible that 1.2346 (or any value you choose) cannot be
>>> precisely represented as you wish, and so converting it to a string
>>> and taking the negative index might be very, very wrong.
>>>
>>> 0.1 is one such number, and it can be demonstrated in python on some
>>> platforms.  Go into the Python REPL and type "0.1" and you might get
>>> "0.10000000000000001" back.
>>>
>>> If this is really important you can store your values as integers --
>>> which are exactly precise -- and handle the decimals yourself.  (In
>>> other words, your own implemention of fixed point values.)
>>>
>>> Joe
>>>
>>> On Sun, Dec 8, 2013 at 2:40 PM,  <jep200404 at columbus.rr.com> wrote:
>>> > On Sun, 8 Dec 2013 14:36:01 -0500, Louis Bogdan <looiebwv at gmail.com>
>>> wrote:
>>> >
>>> >> num is calculated value 1.2346
>>> >> a=num(-1) is indicating the numeral "6" with negative indexing
>>> notation.
>>> >> b=num(-2) is indicating the numeral "4"   "         "
>>> >
>>> > I question the sanity of do so. Nonetheless.
>>> >
>>> > num = 1.2346
>>> > a = str(num)[-1]
>>> > b = str(num)[-2]
>>> >
>>> > print num, a, b
>>> >
>>> > _______________________________________________
>>> > CentralOH mailing list
>>> > CentralOH at python.org
>>> > https://mail.python.org/mailman/listinfo/centraloh
>>> _______________________________________________
>>> CentralOH mailing list
>>> CentralOH at python.org
>>> https://mail.python.org/mailman/listinfo/centraloh
>>>
>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From looiebwv at gmail.com  Mon Dec  9 20:44:02 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Mon, 9 Dec 2013 14:44:02 -0500
Subject: [CentralOH] Define The Problem, Then Solve
In-Reply-To: <20131209104223.0cf0adde.jep200404@columbus.rr.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <20131208144010.16e1a950.jep200404@columbus.rr.com>
 <CAOxvq7xw94Q4LvzxSHtgVdq6ynPSin-Zfis1j3xS9hFJ0VsZeQ@mail.gmail.com>
 <CACLJ_dG4M51vg0RfsVFqmsDuGmLqCocvxDnPwwYs296HmTuVtQ@mail.gmail.com>
 <CAChFk2Y8cUJSCLgjpvETXQpsVu0kjqgESf4SbvHX2=OrzXmwHA@mail.gmail.com>
 <20131209104223.0cf0adde.jep200404@columbus.rr.com>
Message-ID: <CAChFk2b3AYO-tTXPkB25zh98_w+MHaTp0QwyB5dXo4QyVu3v1g@mail.gmail.com>

As I mentioned to Brian, the problem is to express my function in Python
understandable language.  To wonder if it might be 1.2346 or 1234.6 or
1234.60 is pointless because it will be 1.2346 or12346. into eternity thru
precision control.  I got started in programming in 1961 which I did in
machine language because I figured the machine knows its own language so I
might as well use it.  After retirement I got a freebee CoC 2 computer and
my "subroutine" works just fine on it.  I can't print anything as printer
ribbon has not been available for years. If Python can't do it, then I just
might use portions of that basic program which I have managed to print out
and create my own butchered basic language.


On Mon, Dec 9, 2013 at 10:42 AM, <jep200404 at columbus.rr.com> wrote:

> On Mon, 9 Dec 2013 10:32:17 -0500, Louis Bogdan <looiebwv at gmail.com>
> wrote:
>
> > If ...
>
> Come to the meeting and after-meeting.
> It will be good place to discuss and define the problem.
>
> Once we have a good definition of the problem,
> solving the problem should be easy.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
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From kurtis.mullins at gmail.com  Mon Dec  9 21:30:51 2013
From: kurtis.mullins at gmail.com (Kurtis Mullins)
Date: Mon, 9 Dec 2013 15:30:51 -0500
Subject: [CentralOH] (no subject)
In-Reply-To: <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
Message-ID: <CAPbEHsdNgs78uyfCDVoHb-Zuo0i+bf+Lc7mwaJVRMp97G-FJmQ@mail.gmail.com>

I would probably use a combination of this post (
http://math.stackexchange.com/questions/10173/extract-each-digit-of-a-number)
and the Python Decimal library for precision.

Another alternative that seems apparent, but I haven't put much thought
into, is using the Decimal library, converting the number into a String,
and grabbing the digit by index.

Sorry I don't have more time to give you some sample code; I have to run.
If you can't solve it, I'll try to help out when I get some free time.

Good luck!


On Sun, Dec 8, 2013 at 4:10 PM, Louis Bogdan <looiebwv at gmail.com> wrote:

> I see that there are some questions about my explanation of what I'm
> trying to do.  Would it clarify things if my explanation read as follows:
> num(-1) denotes right-hand most digit of num in index position notation
> num(-2) denotes the 3rd position digit of num in index position notation.
>
> I don't know how to say it in computer language, that's why I'm asking for
> your help. Lou
>
>
> On Sun, Dec 8, 2013 at 2:49 PM, Brian Costlow <brian.costlow at gmail.com>wrote:
>
>> This was my quick & dirt response to an email from Louis, and Louis
>> reply, which I have not digested yet. I pointed him at the list as I'm kind
>> of buried with some other stuff this weekend.
>>
>>  You get the same rounding, will take any numeric or a string
>> representing numeric, no float imprecision, no weird string manipulation.
>>
>> >>> from decimal import Decimal as D
>> >>> multiplier_val = D('2000')
>> >>> quant_val = D('1')
>> >>> def custom_round(number):
>> ...   number = D(str(number))
>> ...   return (number * multiplier_val).quantize(quant_val) /
>> multiplier_val
>>
>> >>> custom_round(1.2340)
>> Decimal('1.234')
>> >>> custom_round(1.2341)
>> Decimal('1.234')
>> >>> custom_round(1.2342)
>> Decimal('1.234')
>> >>> custom_round(1.2343)
>> Decimal('1.2345')
>> >>> custom_round(1.2346)
>> Decimal('1.2345')
>> >>> custom_round(1.2347)
>> Decimal('1.2345')
>> >>> custom_round(1.2348)
>> Decimal('1.235')
>> >>> custom_round(1.2349)
>> Decimal('1.235')
>>
>>   I'm so familiar with the details of my invention and its ramifications
>> that I didn't provide you with enough details. to explain my approach. I am
>> looking to make this a subroutine for the following reasons:
>> 1. For various applications, there can be many number, N inputs.
>> 2. For each N input, there can be as many as 30 variable incremental
>> modifications to N, each modification requiring that "subroutine" to make
>> sure that N is in suitable form for later usage.
>> 3. The program to run this only requires the input of N and formula
>> created range of increments thus negating any access to N variations and
>> increments during  the cycle.
>> 4. So with this "subroutine" I have .0002" absolute positional accuracy
>> with .0005" increment control  and other accuracies can be obtained with
>> positional variations.  I hope this clarifies my original email.   Lou
>>
>>
>>
>>
>> On Sun, Dec 8, 2013 at 2:36 PM, Louis Bogdan <looiebwv at gmail.com> wrote:
>>
>>> I will start out by saying,"Have you heard that a LITTLE bit of
>>> knowledge is a dangerous thing?"  Well, I am the Poster Boy for that
>>> saying.
>>>
>>> num is calculated value 1.2346
>>> a=num(-1) is indicating the numeral "6" with negative indexing notation.
>>> b=num(-2) is indicating the numeral "4"   "         "
>>> "              ".
>>>
>>> if numeral "6" is greater than "7" make numeral "6" a "0" and increment
>>> the "4" to "5".
>>> elif numeral "6" is less than"3", meaning a "0", "1", or "2", make it a
>>> "0".
>>> else none of the above conditions apply, make numeral "6" a "5".
>>>
>>> EXAMPLE: 1.2340, 1.2341, 1.2342 become 1.2340
>>>                    1.2348, 1.2349 become 1.2350
>>>                    1.2343, 1/2344, 1.2345, 1.2346. 1.2347 become 1.2345.
>>>
>>> So with the "Bogdan" rounding, I am never more than .0002" off
>>> calculated position.
>>> I then divide the modified num 1.2345 by .0005 and get 2469 which is the
>>> number of steps required of the stepper motor to provide a movement of
>>> 1.2345" (-.0001" from theoretical.)
>>>
>>> I hope that explains MY way of talking to a computer.  How would you
>>> talk to Python and say the same thing and Python says,"MAN, I know what you
>>> want!?  Lou
>>>
>>>
>>> On Sun, Dec 8, 2013 at 11:34 AM, Andrew Fitzgerald <
>>> andrewcfitzgerald at gmail.com> wrote:
>>>
>>>> Hi Lou,
>>>>
>>>> Could you perhaps provide a summary of what that code is supposed to do?
>>>>
>>>> Right now you're assigning num the numeric value 1.2346 on the first
>>>> line.
>>>>
>>>> You're then attempting to call num as a function on the next 2 lines.
>>>>
>>>> This won't work because num hasn't been defined as a function anywhere,
>>>> and if it was the function is overwritten by the value 1.2346 on the first
>>>> line.
>>>>
>>>>
>>>> The part below that (if/else) looks like it should work if a and b are
>>>> assigned numeric values.
>>>>
>>>> -Andrew Fitzgerald
>>>>
>>>>
>>>>  On Sun, Dec 8, 2013 at 11:09 AM, Louis Bogdan <looiebwv at gmail.com>wrote:
>>>>
>>>>>  Hi folks @central oh/python:
>>>>>
>>>>>
>>>>>
>>>>> As a recent subscriber, I received notice of your Dec 9 meeting from
>>>>> Brian.  As I am working on a program to go along with a recently
>>>>> filed patent, and am totally new to Python, I sent him a proposed
>>>>> ?subroutine?.  This is used repetitively within the program.  Since I
>>>>> sent it to Brian, I have done some more research and have come up with a
>>>>> better version as follows:
>>>>>
>>>>>
>>>>>
>>>>> num = 1.2346
>>>>>
>>>>> a = num(-1)
>>>>>
>>>>> b = num(-2)
>>>>>
>>>>> if a >7:
>>>>>
>>>>>      a = 0
>>>>>
>>>>>      b+ =1
>>>>>
>>>>> elif a<3:
>>>>>
>>>>>      a = 0
>>>>>
>>>>> else:
>>>>>
>>>>>       a = 5
>>>>>
>>>>>
>>>>>
>>>>> As each stepper motor step equals .0005? of movement, with the above I
>>>>> can get .0002? absolute positional accuracy with a .0005? control
>>>>> increment. I have looked at some of the Python ?round? statements and
>>>>> examples and don?t fully understand them so as an ?ole? retired engunear,
>>>>> (does 93 qualify me) I thunk up my own way of doing things.  Maybe
>>>>> some of you young ones can teach an ole man how to do things better.
>>>>>
>>>>>
>>>>>
>>>>> This routine also has application in several other projects I have
>>>>> under consideration. Would something like this, if it works, be a Python
>>>>> library item?
>>>>>
>>>>>
>>>>>
>>>>> If any of you can ?tweek? the above into working order I would
>>>>> appreciate it.  I do have some other questions for you.  What do I
>>>>> need to buy to get started with RPi?  I will be using my Apple
>>>>> computer.
>>>>>
>>>>>
>>>>>
>>>>> Thank you for any comments you might have.  Lou Bigdan
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> CentralOH mailing list
>>>>> CentralOH at python.org
>>>>> https://mail.python.org/mailman/listinfo/centraloh
>>>>>
>>>>>
>>>>
>>>> _______________________________________________
>>>> CentralOH mailing list
>>>> CentralOH at python.org
>>>> https://mail.python.org/mailman/listinfo/centraloh
>>>>
>>>>
>>>
>>> _______________________________________________
>>> CentralOH mailing list
>>> CentralOH at python.org
>>> https://mail.python.org/mailman/listinfo/centraloh
>>>
>>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From brian.costlow at gmail.com  Mon Dec  9 21:43:20 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Mon, 9 Dec 2013 15:43:20 -0500
Subject: [CentralOH] Better Problem Description.
In-Reply-To: <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
References: <CACLJ_dE58juo6FvJ3KXPzc094ZLy1RTGpqx3yHJ4EmJ_MbvoWg@mail.gmail.com>
 <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
Message-ID: <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>

Louis,

Here is a sort-of pythonic implementation of your algorithm. There's some
non idiomatic stuff here because I think it's easier for a new Python
person to follow. It takes a string which contains a representation of a
decimal number as input. This will only give correct output if the number
has four places to the right of the decimal. It will also have issues if
the string passed in is not a number. And one more thing...read on

# Used as a simple hash to lookup new last digit
ROUNDING_LOOKUP = { '0':'0', '1':'0', '2':'0', '3':'5', '4':'5',
    '5':'5', '6':'5', '7':'5', '8':'0', '9':'0', }

def bogdan_round(num_as_string):
    '''Round to 0.0005 step

    Input must be a string representing a decimal number, with
    four places to right of decimal. Anything else WILL break.
    Negative values WILL NOT move in correct direction'''

    # part that won't change, uses slice notation, given 1.2345 as input
becomes 1.23
    prefix = num_as_string[:-2]
    # given 1.2345 becomes 4
    next_to_last_digit = num_as_string[-2:-1]
    # given 1.2345 becomes 5
    last_digit = num_as_stringx[-1:]
    next_to_last_as_int = int(next_to_last_digit)

    if next_to_last_as_int > 7:
        if next_to_last_as_int == 9:
            next_to_last_digit = '0'
        else:
            next_to_last_digit = str(next_to_last_as_int + 1)
    return prefix + next_to_last_digit + ROUNDING_LOOKUP[last_digit]

Except there is a huge bug here.

1.2346 returns 1.2345
1.2349 returns 1.2350
but
1.2399 returns 1.2300 NOT the correct 1.2400 which is what happens when you
try to play with isolated digits as a string.

To fix that requires traversing the rest of the string in a loop adjusting
digits. It's better to do math. Returning to my earlier solution, with a
couple of tweaks.

All computers have imprecision when doing floating point math, because of
precision limitations moving between decimal and the actual binary
implementation of the numbers. This is not unique to Python, but any
language that abstracts the idea of a float and targets multiple
architectures.

Python has a Decimal library that allows you to do fixed point decimal
math, or do floating point that will notify you if precision is lost. This
does the same as the above, plus it handles ints and floats as input,
negative values:

# Use the decimal lib
from decimal import Decimal as D

# Since we are rounding to closest 0.0005, we can't just use the quant
method
# but we have to multiply so we can do integer rounding then divide back
MULTIPLIER = D('2000')

# Number can be int, string, or in Python 2.7 or >, a float
def custom_round(number):
    number = D(number) # create a decimal type
    # multiply so we can round to nearest int
    adjusted_number = number * MULTIPLIER
    # round, divide back, and return result in one step
    return adjusted_number.to_integral_value() / MULTIPLIER

Here's the function in action, showing the result:

>>> custom_round('1.2340')
Decimal('1.234')
>>> custom_round('1.2341')
Decimal('1.234')
>>> custom_round('1.2342')
Decimal('1.234')
>>> custom_round('1.2343')
Decimal('1.2345')
>>> custom_round('1.2344')
Decimal('1.2345')
>>> custom_round('1.2345')
Decimal('1.2345')
>>> custom_round('1.2346')
Decimal('1.2345')
>>> custom_round('1.2347')
Decimal('1.2345')
>>> custom_round('1.2348')
Decimal('1.235')
>>> custom_round('1.2349')
Decimal('1.235')

















On Mon, Dec 9, 2013 at 12:56 PM, Louis Bogdan <looiebwv at gmail.com> wrote:

> First off Brian, thank you for your interest in helping me.  So let's
> start from the beginning.  The number comes from a keyboard input that is
> requested with 4 decimal input and is modified with an imbedded formula.
> In this application the keyboard number can vary from integer to integer
> plus 4 decimal.  This modified number, "num", is used to control a stepper
> motor where each step equals 0.0005" of linear motion.  My function rounds
> "num" in such a manner that the maximum error is 0.0002", which in this
> application is acceptable.  The initial number may be modified as much as
> 30 times in a cycle.  These modifications are so handled that in
> engineering parlance I "baseline" dimension rather that "chain" so that
> each increment is within 0.0002" of true location rather than a possible
> maximum accumulative error of 0.0066".  All that I can and have handled.
> What I need is to put my "rounding" function into Python language. One
> comment I received was to use only integers.  That would be no problem, we
> would adjust the units and tens digit as necessary and accomplish the same
> thing. It would be: motor steps equals num(decimal)/0.0005 or
> num(integer)/5 as I have shown in one of my emails.  As far as the comment
> of "other" accuracies can be totally ignored in the present discussion.
>
> Now I know that Python does rounding which I don't understand and have not
> found any decent, understandable explanation how it does it.  I understand
> rounding, even way back when I was proficient with the abacus.
>
> I hope this is some claification and if not, let me know.  Lou
>
>
> On Mon, Dec 9, 2013 at 10:53 AM, Brian Costlow <brian.costlow at gmail.com>wrote:
>
>> Hi Louis,
>>
>> I read through all the group postings real quick this morning, and here's
>> my take.
>>
>> What Jim is asking for (he's our resident elder curmudgeon, although in
>> your case he could probably be your grandson.) is to step back and describe
>> the problem in English.
>>
>> You have given us an algorithm, and asked us to help you code it in
>> Python. That algorithm is best encoded in Python via string manipulation,
>> which is not really what you should be doing if you are trying to do math.
>>
>> So, we want a generic description of the problem because we may find a
>> better algorithm entirely.
>>
>> We also need to know where the input is coming from and where it is used
>> after, because if you have floating point values coming in, and going out,
>> then not only is string manipulation 'extra' work, it may bite you.
>>
>> Last, it's unclear whether the 0.0005 step value ever needs to change.
>> Thus Jim's comment about magic numbers. I think your line that said this: "other
>> accuracies can be obtained with positional variations" implies that 0.0005
>> step might change and be some other value. But it's not clear.
>>
>> In my code I sent you earlier, 'custom_round' IS a subroutine (we usually
>> say procedure or function in python-speak) that does exactly what you need.
>> It doesn't do string manipulation, it does real math, but it will accept a
>> string or any numeric type as input.
>>
>> You can also modify it so that the 0.0005 is changeable.There are a
>> couple of design approaches to doing that, and the one you should use
>> partly depends on the rest of your program design.
>>
>> Coding something in any language is not merely figuring a psuedo-code
>> algorithm and then forcing the language to fit your algorithm.
>>
>> It's learning the idioms and built-in tools of the language.
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
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From jep200404 at columbus.rr.com  Mon Dec  9 23:06:34 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Mon, 9 Dec 2013 17:06:34 -0500
Subject: [CentralOH] State The Problem Simply
In-Reply-To: <20131208170601.52548c40.jep200404@columbus.rr.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
 <20131208170601.52548c40.jep200404@columbus.rr.com>
Message-ID: <20131209170634.3c426a2f.jep200404@columbus.rr.com>

Lou, 

Does the following correctly describe what you want to accomplish? 

    Given position d and stepper motor resolution steps_per_unit, 
    calculate the position closest to d that a 
    steps_per_unit stepper motor can achieve. 

A terse yes or no without explanation is best.

From looiebwv at gmail.com  Tue Dec 10 00:59:01 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Mon, 9 Dec 2013 18:59:01 -0500
Subject: [CentralOH] Better Problem Description.
In-Reply-To: <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>
References: <CACLJ_dE58juo6FvJ3KXPzc094ZLy1RTGpqx3yHJ4EmJ_MbvoWg@mail.gmail.com>
 <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
 <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>
Message-ID: <CAChFk2bV8Ho8xSGDsrEkTp6AERKeFmyaW9QRZeqkvrLS8h4abw@mail.gmail.com>

Hi Brian:  You bring up an interesting point. If num is 1.2399 would result
in 1.2300 my way.  In looking at that there is a real easy fix that also
simplifies the function as follows:
num = 1.2399
if num[-1] >7
     num+=2     #this will make num 1.2398 ,1.2399 = 1.2400 or 1.2401.
elif num[-1]<3
     num[-1]= 0      # this will make num 1.2401,1.2402 =1.2400
else:
     num[-1] = 5    #nom 1.2394, 1.2395, 1.2396,1.2397 will =1.2395

I ran several "numbers" and found 2 occasions with a .0099 condition.  Does
this make any sense?
A num 1.2398 or 1.2399 would obviate the else statement but we do not have
access to the calculations so it should be standard.


On Mon, Dec 9, 2013 at 3:43 PM, Brian Costlow <brian.costlow at gmail.com>wrote:

> Louis,
>
> Here is a sort-of pythonic implementation of your algorithm. There's some
> non idiomatic stuff here because I think it's easier for a new Python
> person to follow. It takes a string which contains a representation of a
> decimal number as input. This will only give correct output if the number
> has four places to the right of the decimal. It will also have issues if
> the string passed in is not a number. And one more thing...read on
>
> # Used as a simple hash to lookup new last digit
> ROUNDING_LOOKUP = { '0':'0', '1':'0', '2':'0', '3':'5', '4':'5',
>     '5':'5', '6':'5', '7':'5', '8':'0', '9':'0', }
>
> def bogdan_round(num_as_string):
>     '''Round to 0.0005 step
>
>     Input must be a string representing a decimal number, with
>     four places to right of decimal. Anything else WILL break.
>     Negative values WILL NOT move in correct direction'''
>
>     # part that won't change, uses slice notation, given 1.2345 as input
> becomes 1.23
>     prefix = num_as_string[:-2]
>     # given 1.2345 becomes 4
>     next_to_last_digit = num_as_string[-2:-1]
>     # given 1.2345 becomes 5
>     last_digit = num_as_stringx[-1:]
>     next_to_last_as_int = int(next_to_last_digit)
>
>     if next_to_last_as_int > 7:
>         if next_to_last_as_int == 9:
>             next_to_last_digit = '0'
>         else:
>             next_to_last_digit = str(next_to_last_as_int + 1)
>     return prefix + next_to_last_digit + ROUNDING_LOOKUP[last_digit]
>
> Except there is a huge bug here.
>
> 1.2346 returns 1.2345
> 1.2349 returns 1.2350
> but
> 1.2399 returns 1.2300 NOT the correct 1.2400 which is what happens when
> you try to play with isolated digits as a string.
>
> To fix that requires traversing the rest of the string in a loop adjusting
> digits. It's better to do math. Returning to my earlier solution, with a
> couple of tweaks.
>
> All computers have imprecision when doing floating point math, because of
> precision limitations moving between decimal and the actual binary
> implementation of the numbers. This is not unique to Python, but any
> language that abstracts the idea of a float and targets multiple
> architectures.
>
> Python has a Decimal library that allows you to do fixed point decimal
> math, or do floating point that will notify you if precision is lost. This
> does the same as the above, plus it handles ints and floats as input,
> negative values:
>
> # Use the decimal lib
> from decimal import Decimal as D
>
> # Since we are rounding to closest 0.0005, we can't just use the quant
> method
> # but we have to multiply so we can do integer rounding then divide back
> MULTIPLIER = D('2000')
>
> # Number can be int, string, or in Python 2.7 or >, a float
> def custom_round(number):
>     number = D(number) # create a decimal type
>     # multiply so we can round to nearest int
>     adjusted_number = number * MULTIPLIER
>     # round, divide back, and return result in one step
>     return adjusted_number.to_integral_value() / MULTIPLIER
>
> Here's the function in action, showing the result:
>
> >>> custom_round('1.2340')
> Decimal('1.234')
> >>> custom_round('1.2341')
> Decimal('1.234')
> >>> custom_round('1.2342')
> Decimal('1.234')
> >>> custom_round('1.2343')
> Decimal('1.2345')
> >>> custom_round('1.2344')
> Decimal('1.2345')
> >>> custom_round('1.2345')
> Decimal('1.2345')
> >>> custom_round('1.2346')
> Decimal('1.2345')
> >>> custom_round('1.2347')
> Decimal('1.2345')
> >>> custom_round('1.2348')
> Decimal('1.235')
> >>> custom_round('1.2349')
> Decimal('1.235')
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> On Mon, Dec 9, 2013 at 12:56 PM, Louis Bogdan <looiebwv at gmail.com> wrote:
>
>> First off Brian, thank you for your interest in helping me.  So let's
>> start from the beginning.  The number comes from a keyboard input that is
>> requested with 4 decimal input and is modified with an imbedded formula.
>> In this application the keyboard number can vary from integer to integer
>> plus 4 decimal.  This modified number, "num", is used to control a stepper
>> motor where each step equals 0.0005" of linear motion.  My function rounds
>> "num" in such a manner that the maximum error is 0.0002", which in this
>> application is acceptable.  The initial number may be modified as much as
>> 30 times in a cycle.  These modifications are so handled that in
>> engineering parlance I "baseline" dimension rather that "chain" so that
>> each increment is within 0.0002" of true location rather than a possible
>> maximum accumulative error of 0.0066".  All that I can and have handled.
>> What I need is to put my "rounding" function into Python language. One
>> comment I received was to use only integers.  That would be no problem, we
>> would adjust the units and tens digit as necessary and accomplish the same
>> thing. It would be: motor steps equals num(decimal)/0.0005 or
>> num(integer)/5 as I have shown in one of my emails.  As far as the comment
>> of "other" accuracies can be totally ignored in the present discussion.
>>
>> Now I know that Python does rounding which I don't understand and have
>> not found any decent, understandable explanation how it does it.  I
>> understand rounding, even way back when I was proficient with the abacus.
>>
>> I hope this is some claification and if not, let me know.  Lou
>>
>>
>> On Mon, Dec 9, 2013 at 10:53 AM, Brian Costlow <brian.costlow at gmail.com>wrote:
>>
>>> Hi Louis,
>>>
>>> I read through all the group postings real quick this morning, and
>>> here's my take.
>>>
>>> What Jim is asking for (he's our resident elder curmudgeon, although in
>>> your case he could probably be your grandson.) is to step back and describe
>>> the problem in English.
>>>
>>> You have given us an algorithm, and asked us to help you code it in
>>> Python. That algorithm is best encoded in Python via string manipulation,
>>> which is not really what you should be doing if you are trying to do math.
>>>
>>> So, we want a generic description of the problem because we may find a
>>> better algorithm entirely.
>>>
>>> We also need to know where the input is coming from and where it is used
>>> after, because if you have floating point values coming in, and going out,
>>> then not only is string manipulation 'extra' work, it may bite you.
>>>
>>> Last, it's unclear whether the 0.0005 step value ever needs to change.
>>> Thus Jim's comment about magic numbers. I think your line that said this: "other
>>> accuracies can be obtained with positional variations" implies that 0.0005
>>> step might change and be some other value. But it's not clear.
>>>
>>> In my code I sent you earlier, 'custom_round' IS a subroutine (we
>>> usually say procedure or function in python-speak) that does exactly what
>>> you need. It doesn't do string manipulation, it does real math, but it will
>>> accept a string or any numeric type as input.
>>>
>>> You can also modify it so that the 0.0005 is changeable.There are a
>>> couple of design approaches to doing that, and the one you should use
>>> partly depends on the rest of your program design.
>>>
>>> Coding something in any language is not merely figuring a psuedo-code
>>> algorithm and then forcing the language to fit your algorithm.
>>>
>>> It's learning the idioms and built-in tools of the language.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>
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From looiebwv at gmail.com  Tue Dec 10 01:01:38 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Mon, 9 Dec 2013 19:01:38 -0500
Subject: [CentralOH] State The Problem Simply
In-Reply-To: <20131209170634.3c426a2f.jep200404@columbus.rr.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
 <20131208170601.52548c40.jep200404@columbus.rr.com>
 <20131209170634.3c426a2f.jep200404@columbus.rr.com>
Message-ID: <CAChFk2avxS0LZch7OjLEhf11H+R7iL3Ana47B8bY+LNsw6difQ@mail.gmail.com>

yes


On Mon, Dec 9, 2013 at 5:06 PM, <jep200404 at columbus.rr.com> wrote:

> Lou,
>
> Does the following correctly describe what you want to accomplish?
>
>     Given position d and stepper motor resolution steps_per_unit,
>     calculate the position closest to d that a
>     steps_per_unit stepper motor can achieve.
>
> A terse yes or no without explanation is best.
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
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From brian.costlow at gmail.com  Tue Dec 10 05:53:37 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Mon, 9 Dec 2013 23:53:37 -0500
Subject: [CentralOH] State The Problem Simply
In-Reply-To: <CAChFk2avxS0LZch7OjLEhf11H+R7iL3Ana47B8bY+LNsw6difQ@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
 <20131208170601.52548c40.jep200404@columbus.rr.com>
 <20131209170634.3c426a2f.jep200404@columbus.rr.com>
 <CAChFk2avxS0LZch7OjLEhf11H+R7iL3Ana47B8bY+LNsw6difQ@mail.gmail.com>
Message-ID: <CACLJ_dG9U+RTb0SueR4g-tnTidJWpDj6Lp8imKvPXa7vN1V5eA@mail.gmail.com>

Follow on.

Is steps_per_unit a constant throughout the life of the program, or is it
expected to change?


On Mon, Dec 9, 2013 at 7:01 PM, Louis Bogdan <looiebwv at gmail.com> wrote:

> yes
>
>
> On Mon, Dec 9, 2013 at 5:06 PM, <jep200404 at columbus.rr.com> wrote:
>
>> Lou,
>>
>> Does the following correctly describe what you want to accomplish?
>>
>>     Given position d and stepper motor resolution steps_per_unit,
>>     calculate the position closest to d that a
>>     steps_per_unit stepper motor can achieve.
>>
>> A terse yes or no without explanation is best.
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From jep200404 at columbus.rr.com  Tue Dec 10 06:23:42 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 10 Dec 2013 00:23:42 -0500
Subject: [CentralOH] Simply Stated Problem Solved Simply
In-Reply-To: <CAChFk2avxS0LZch7OjLEhf11H+R7iL3Ana47B8bY+LNsw6difQ@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
 <20131208170601.52548c40.jep200404@columbus.rr.com>
 <20131209170634.3c426a2f.jep200404@columbus.rr.com>
 <CAChFk2avxS0LZch7OjLEhf11H+R7iL3Ana47B8bY+LNsw6difQ@mail.gmail.com>
Message-ID: <20131210002342.0c82e1de.jep200404@columbus.rr.com>

On Mon, 9 Dec 2013 19:01:38 -0500, Louis Bogdan <looiebwv at gmail.com> wrote:

> On Mon, Dec 9, 2013 at 5:06 PM, <jep200404 at columbus.rr.com> wrote:

> > Does the following correctly describe what you want to accomplish?
> >
> >     Given position d and stepper motor resolution steps_per_unit,
> >     calculate the position closest to d that a
> >     steps_per_unit stepper motor can achieve.
> >
> > A terse yes or no without explanation is best.

> yes

Good. That's the clarity and simplicity that both you and I needed. 
I think I already solved that problem.
See the goo() function near the bottom of an earlier post[1].

I exercised that code in Ipython Notebook and brought it to 
tonight's meeting to show, but you were not there, 
so I did not show it. I have attached a cleaned up version 
of that notebook in the attached tarball. 

You can play with that notebook, either by installing 
Ipython Notebook[2] or running it on a remote server, 
such as Ipython Notebook Viewer[3].
Scrutinize the output of cell #4.
Study the foo() function also. You might find it to be handy 
for determining how many stepper motor steps to do. 

[1] https://mail.python.org/pipermail/centraloh/2013-December/001919.html
    That post might be longer than you thought.
    Scroll all the way to the bottom.

[2] IPython & Notebook on Xubuntu 12.10 Desktop i386
    https://mail.python.org/pipermail/centraloh/2013-February/index.html

[3] http://nbviewer.ipython.org/
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From nludban at columbus.rr.com  Tue Dec 10 14:22:39 2013
From: nludban at columbus.rr.com (Neil Ludban)
Date: Tue, 10 Dec 2013 08:22:39 -0500
Subject: [CentralOH] Better Problem Description.
In-Reply-To: <CAChFk2bV8Ho8xSGDsrEkTp6AERKeFmyaW9QRZeqkvrLS8h4abw@mail.gmail.com>
References: <CACLJ_dE58juo6FvJ3KXPzc094ZLy1RTGpqx3yHJ4EmJ_MbvoWg@mail.gmail.com>
 <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
 <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>
 <CAChFk2bV8Ho8xSGDsrEkTp6AERKeFmyaW9QRZeqkvrLS8h4abw@mail.gmail.com>
Message-ID: <20131210082239.13d368cf.nludban@columbus.rr.com>

On Mon, 9 Dec 2013 18:59:01 -0500
Louis Bogdan <looiebwv at gmail.com> wrote:
...
> > On Mon, Dec 9, 2013 at 12:56 PM, Louis Bogdan <looiebwv at gmail.com> wrote:
> >> Now I know that Python does rounding which I don't understand and have
> >> not found any decent, understandable explanation how it does it.  I
> >> understand rounding, even way back when I was proficient with the abacus.

It's really quantization errors, not rounding.  If binary integers
are expressed as a sum of numbers from the set {1, 2, 4, 8, 16, ...}
then binary floating point numbers (from a very simplistic viewpoint)
add to that set the fractions {1/2, 1/4, 1/8, 1/16, ...}.  64-bit
doubles (the typical Python "float" type) enables 53 consecutive
values from that combined set:

http://en.wikipedia.org/wiki/Double_precision_floating-point_format

So numbers like 1, 1+1/2, 1+1/4, 1+1/8, can be represented exactly
in decimal and binary (the minus sign is added here to force the
bin function to output all 64 bits):

--> import struct
--> bin(struct.unpack('Q', struct.pack('d', float('-1.0000')))[0])
'0b1011111111110000000000000000000000000000000000000000000000000000'
--> bin(struct.unpack('Q', struct.pack('d', float('-1.5000')))[0])
'0b1011111111111000000000000000000000000000000000000000000000000000'
--> bin(struct.unpack('Q', struct.pack('d', float('-1.2500')))[0])
'0b1011111111110100000000000000000000000000000000000000000000000000'
--> bin(struct.unpack('Q', struct.pack('d', float('-1.1250')))[0])
'0b1011111111110010000000000000000000000000000000000000000000000000'


1+1/10 works in decimal, but is a repeating pattern in binary:
--> bin(struct.unpack('Q', struct.pack('d', float('-1.1000')))[0])
'0b1011111111110001100110011001100110011001100110011001100110011010'


1+1/3 repeats in both decimal and binary:
--> -4/3.
-1.3333333333333333
--> bin(struct.unpack('Q', struct.pack('d', float(-4/3.)))[0])
'0b1011111111110101010101010101010101010101010101010101010101010101'


And then there's the weird stuff that may concern you:

--> bin(struct.unpack('Q', struct.pack('d', float(-4/3. * 1000 / 1000)))[0])
'0b1011111111110101010101010101010101010101010101010101010101010101'
--> bin(struct.unpack('Q', struct.pack('d', float(-4/3. + 1000 - 1000)))[0])
'0b1011111111110101010101010101010101010101010101010101011000000000'
--> -4/3. + 1000 - 1000
-1.3333333333333712

The result of the last example can vary depending on the compiler
and optimization flags, whether the code runs on the main FPU or
vector coprocessor (eg, MMX), level of IEEE-754 compliance (which
varies from none for early Crays to partly for early NVIDIA GPUs to
full for most modern desktops), and any non-standard options (eg,
rounding mode and denormal truncation) which other parts of your
application or supporting libraries may have set...


Hope that helps.

From brian.costlow at gmail.com  Tue Dec 10 14:36:53 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Tue, 10 Dec 2013 08:36:53 -0500
Subject: [CentralOH] Simply Stated Problem Solved Simply
In-Reply-To: <20131210002342.0c82e1de.jep200404@columbus.rr.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
 <20131208170601.52548c40.jep200404@columbus.rr.com>
 <20131209170634.3c426a2f.jep200404@columbus.rr.com>
 <CAChFk2avxS0LZch7OjLEhf11H+R7iL3Ana47B8bY+LNsw6difQ@mail.gmail.com>
 <20131210002342.0c82e1de.jep200404@columbus.rr.com>
Message-ID: <CACLJ_dGtJ97F7Ty1yTARcPOXc4zyfPkvTzB_hTsW7y_-KLFgcw@mail.gmail.com>

The solution here is almost identical to the one I posted, except goo()
allows floating point discrepancies to creep in. Which usually will just
wash out, but could potentially round to the wrong step. That's dependent
on the expected range of d. Using the decimal library helps to prevent
that, and/or signals when you have an issue.

It's worth reading through the module's doc and understanding for this type
of application.


On Tue, Dec 10, 2013 at 12:23 AM, <jep200404 at columbus.rr.com> wrote:

> On Mon, 9 Dec 2013 19:01:38 -0500, Louis Bogdan <looiebwv at gmail.com>
> wrote:
>
> > On Mon, Dec 9, 2013 at 5:06 PM, <jep200404 at columbus.rr.com> wrote:
>
> > > Does the following correctly describe what you want to accomplish?
> > >
> > >     Given position d and stepper motor resolution steps_per_unit,
> > >     calculate the position closest to d that a
> > >     steps_per_unit stepper motor can achieve.
> > >
> > > A terse yes or no without explanation is best.
>
> > yes
>
> Good. That's the clarity and simplicity that both you and I needed.
> I think I already solved that problem.
> See the goo() function near the bottom of an earlier post[1].
>
> I exercised that code in Ipython Notebook and brought it to
> tonight's meeting to show, but you were not there,
> so I did not show it. I have attached a cleaned up version
> of that notebook in the attached tarball.
>
> You can play with that notebook, either by installing
> Ipython Notebook[2] or running it on a remote server,
> such as Ipython Notebook Viewer[3].
> Scrutinize the output of cell #4.
> Study the foo() function also. You might find it to be handy
> for determining how many stepper motor steps to do.
>
> [1] https://mail.python.org/pipermail/centraloh/2013-December/001919.html
>     That post might be longer than you thought.
>     Scroll all the way to the bottom.
>
> [2] IPython & Notebook on Xubuntu 12.10 Desktop i386
>     https://mail.python.org/pipermail/centraloh/2013-February/index.html
>
> [3] http://nbviewer.ipython.org/
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From jep200404 at columbus.rr.com  Tue Dec 10 14:57:34 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 10 Dec 2013 08:57:34 -0500
Subject: [CentralOH] Range of Movement
In-Reply-To: <CACLJ_dGtJ97F7Ty1yTARcPOXc4zyfPkvTzB_hTsW7y_-KLFgcw@mail.gmail.com>
References: <CAChFk2ZUWNBeZb94=WmiSVxN-3YHkp5jE2f5Pb-p37cp78HhvA@mail.gmail.com>
 <CACkx_dC6Ee3rhFQYGCgajhG-P59=PQ1xJBhzazmy9HLfe4ssng@mail.gmail.com>
 <CAChFk2a+0aQ-BZ5+FgWyT25fFUK+rHf+ZoHCL87ZUmtDLxihGQ@mail.gmail.com>
 <CACLJ_dFTFGdaj8Av7nJhWppKNm6RtOezLya7=2VYtBdYmg5qYA@mail.gmail.com>
 <CAChFk2Zcmc998+UQ0BGWXn8oDp4oFeGR+O3WrwbVq=fj+Lhimw@mail.gmail.com>
 <20131208170601.52548c40.jep200404@columbus.rr.com>
 <20131209170634.3c426a2f.jep200404@columbus.rr.com>
 <CAChFk2avxS0LZch7OjLEhf11H+R7iL3Ana47B8bY+LNsw6difQ@mail.gmail.com>
 <20131210002342.0c82e1de.jep200404@columbus.rr.com>
 <CACLJ_dGtJ97F7Ty1yTARcPOXc4zyfPkvTzB_hTsW7y_-KLFgcw@mail.gmail.com>
Message-ID: <20131210085734.560d110d.jep200404@columbus.rr.com>

Lou, how far can your stepper motor(s) move things? 

On Tue, 10 Dec 2013 08:36:53 -0500, Brian Costlow <brian.costlow at gmail.com> wrote:

> ... goo()
> allows floating point discrepancies to creep in. Which usually will just
> wash out, but could potentially round to the wrong step. That's dependent
> on the expected range of d. 

Again, the hard part is getting a good description of the 
problem. 


From looiebwv at gmail.com  Tue Dec 10 16:24:08 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Tue, 10 Dec 2013 10:24:08 -0500
Subject: [CentralOH] Better Problem Description.
In-Reply-To: <20131210082239.13d368cf.nludban@columbus.rr.com>
References: <CACLJ_dE58juo6FvJ3KXPzc094ZLy1RTGpqx3yHJ4EmJ_MbvoWg@mail.gmail.com>
 <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
 <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>
 <CAChFk2bV8Ho8xSGDsrEkTp6AERKeFmyaW9QRZeqkvrLS8h4abw@mail.gmail.com>
 <20131210082239.13d368cf.nludban@columbus.rr.com>
Message-ID: <CAChFk2Y2kGKqzPrFcUKWYhBQZ8mJr=RK7bsxC1nSB-ysCQEKGQ@mail.gmail.com>

It seems that I'm having a problem in getting my point across as to what I
would like to do, so let's try another approach.

I have a number, 1.2348 and it is of no consequence or interest where it
came from, etc.  I would like to manipulate the right hand most digit so
that if it is greater that 7, I would increment it by 2 to 0 and end up
with the number being either 1.2350 or 1.2351.

In like manner I would just change the right hand most digit to 0 as this
would have no effect on any other digits, I would end up with the number
being 1.2340.

Now if the right hand digit was not greater than 7 nor less than 3, it fall
into the range of 3-8 and digits 3, 4, 5 ,6 &7 I change to digit 5

The end result of the above I will have a number whose right hand digit
will be either  0 or 5.  And here again, what happens next is of no
consequence or interest to anyone but me.  But to satisfy some people's
curiosity, the above number was derived from a keypad input, two integer
four decimal, and manipulated by an internal equation.  The finally derived
number will then manipulated into an integer which will the number of steps
required to make a linear movement equal to the above number of inches.

NOW!! HOW DO I SAY THAT IN PYTHON?




On Tue, Dec 10, 2013 at 8:22 AM, Neil Ludban <nludban at columbus.rr.com>wrote:

> On Mon, 9 Dec 2013 18:59:01 -0500
> Louis Bogdan <looiebwv at gmail.com> wrote:
> ...
> > > On Mon, Dec 9, 2013 at 12:56 PM, Louis Bogdan <looiebwv at gmail.com>
> wrote:
> > >> Now I know that Python does rounding which I don't understand and have
> > >> not found any decent, understandable explanation how it does it.  I
> > >> understand rounding, even way back when I was proficient with the
> abacus.
>
> It's really quantization errors, not rounding.  If binary integers
> are expressed as a sum of numbers from the set {1, 2, 4, 8, 16, ...}
> then binary floating point numbers (from a very simplistic viewpoint)
> add to that set the fractions {1/2, 1/4, 1/8, 1/16, ...}.  64-bit
> doubles (the typical Python "float" type) enables 53 consecutive
> values from that combined set:
>
> http://en.wikipedia.org/wiki/Double_precision_floating-point_format
>
> So numbers like 1, 1+1/2, 1+1/4, 1+1/8, can be represented exactly
> in decimal and binary (the minus sign is added here to force the
> bin function to output all 64 bits):
>
> --> import struct
> --> bin(struct.unpack('Q', struct.pack('d', float('-1.0000')))[0])
> '0b1011111111110000000000000000000000000000000000000000000000000000'
> --> bin(struct.unpack('Q', struct.pack('d', float('-1.5000')))[0])
> '0b1011111111111000000000000000000000000000000000000000000000000000'
> --> bin(struct.unpack('Q', struct.pack('d', float('-1.2500')))[0])
> '0b1011111111110100000000000000000000000000000000000000000000000000'
> --> bin(struct.unpack('Q', struct.pack('d', float('-1.1250')))[0])
> '0b1011111111110010000000000000000000000000000000000000000000000000'
>
>
> 1+1/10 works in decimal, but is a repeating pattern in binary:
> --> bin(struct.unpack('Q', struct.pack('d', float('-1.1000')))[0])
> '0b1011111111110001100110011001100110011001100110011001100110011010'
>
>
> 1+1/3 repeats in both decimal and binary:
> --> -4/3.
> -1.3333333333333333
> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3.)))[0])
> '0b1011111111110101010101010101010101010101010101010101010101010101'
>
>
> And then there's the weird stuff that may concern you:
>
> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3. * 1000 /
> 1000)))[0])
> '0b1011111111110101010101010101010101010101010101010101010101010101'
> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3. + 1000 -
> 1000)))[0])
> '0b1011111111110101010101010101010101010101010101010101011000000000'
> --> -4/3. + 1000 - 1000
> -1.3333333333333712
>
> The result of the last example can vary depending on the compiler
> and optimization flags, whether the code runs on the main FPU or
> vector coprocessor (eg, MMX), level of IEEE-754 compliance (which
> varies from none for early Crays to partly for early NVIDIA GPUs to
> full for most modern desktops), and any non-standard options (eg,
> rounding mode and denormal truncation) which other parts of your
> application or supporting libraries may have set...
>
>
> Hope that helps.
>
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From joe at joeshaw.org  Tue Dec 10 16:31:48 2013
From: joe at joeshaw.org (Joe Shaw)
Date: Tue, 10 Dec 2013 10:31:48 -0500
Subject: [CentralOH] Better Problem Description.
In-Reply-To: <CAChFk2Y2kGKqzPrFcUKWYhBQZ8mJr=RK7bsxC1nSB-ysCQEKGQ@mail.gmail.com>
References: <CACLJ_dE58juo6FvJ3KXPzc094ZLy1RTGpqx3yHJ4EmJ_MbvoWg@mail.gmail.com>
 <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
 <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>
 <CAChFk2bV8Ho8xSGDsrEkTp6AERKeFmyaW9QRZeqkvrLS8h4abw@mail.gmail.com>
 <20131210082239.13d368cf.nludban@columbus.rr.com>
 <CAChFk2Y2kGKqzPrFcUKWYhBQZ8mJr=RK7bsxC1nSB-ysCQEKGQ@mail.gmail.com>
Message-ID: <CAOxvq7z_P7TOCThfSTOL8xi4iZo=rx2YjAGKxw3sUEU9n4EcGg@mail.gmail.com>

Hi,

To put it into pseudocode:

if last_digit < 3:
    last_digit = 0
elif last_digit < 8:
    last_digit = 5
else:
    last_digit = 0
    next_to_last_digit += 1

Is that correct?

On Tue, Dec 10, 2013 at 10:24 AM, Louis Bogdan <looiebwv at gmail.com> wrote:
> It seems that I'm having a problem in getting my point across as to what I
> would like to do, so let's try another approach.
>
> I have a number, 1.2348 and it is of no consequence or interest where it
> came from, etc.  I would like to manipulate the right hand most digit so
> that if it is greater that 7, I would increment it by 2 to 0 and end up with
> the number being either 1.2350 or 1.2351.
>
> In like manner I would just change the right hand most digit to 0 as this
> would have no effect on any other digits, I would end up with the number
> being 1.2340.
>
> Now if the right hand digit was not greater than 7 nor less than 3, it fall
> into the range of 3-8 and digits 3, 4, 5 ,6 &7 I change to digit 5
>
> The end result of the above I will have a number whose right hand digit will
> be either  0 or 5.  And here again, what happens next is of no consequence
> or interest to anyone but me.  But to satisfy some people's curiosity, the
> above number was derived from a keypad input, two integer four decimal, and
> manipulated by an internal equation.  The finally derived number will then
> manipulated into an integer which will the number of steps required to make
> a linear movement equal to the above number of inches.
>
> NOW!! HOW DO I SAY THAT IN PYTHON?
>
>
>
>
> On Tue, Dec 10, 2013 at 8:22 AM, Neil Ludban <nludban at columbus.rr.com>
> wrote:
>>
>> On Mon, 9 Dec 2013 18:59:01 -0500
>> Louis Bogdan <looiebwv at gmail.com> wrote:
>> ...
>> > > On Mon, Dec 9, 2013 at 12:56 PM, Louis Bogdan <looiebwv at gmail.com>
>> > > wrote:
>> > >> Now I know that Python does rounding which I don't understand and
>> > >> have
>> > >> not found any decent, understandable explanation how it does it.  I
>> > >> understand rounding, even way back when I was proficient with the
>> > >> abacus.
>>
>> It's really quantization errors, not rounding.  If binary integers
>> are expressed as a sum of numbers from the set {1, 2, 4, 8, 16, ...}
>> then binary floating point numbers (from a very simplistic viewpoint)
>> add to that set the fractions {1/2, 1/4, 1/8, 1/16, ...}.  64-bit
>> doubles (the typical Python "float" type) enables 53 consecutive
>> values from that combined set:
>>
>> http://en.wikipedia.org/wiki/Double_precision_floating-point_format
>>
>> So numbers like 1, 1+1/2, 1+1/4, 1+1/8, can be represented exactly
>> in decimal and binary (the minus sign is added here to force the
>> bin function to output all 64 bits):
>>
>> --> import struct
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.0000')))[0])
>> '0b1011111111110000000000000000000000000000000000000000000000000000'
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.5000')))[0])
>> '0b1011111111111000000000000000000000000000000000000000000000000000'
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.2500')))[0])
>> '0b1011111111110100000000000000000000000000000000000000000000000000'
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.1250')))[0])
>> '0b1011111111110010000000000000000000000000000000000000000000000000'
>>
>>
>> 1+1/10 works in decimal, but is a repeating pattern in binary:
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.1000')))[0])
>> '0b1011111111110001100110011001100110011001100110011001100110011010'
>>
>>
>> 1+1/3 repeats in both decimal and binary:
>> --> -4/3.
>> -1.3333333333333333
>> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3.)))[0])
>> '0b1011111111110101010101010101010101010101010101010101010101010101'
>>
>>
>> And then there's the weird stuff that may concern you:
>>
>> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3. * 1000 /
>> 1000)))[0])
>> '0b1011111111110101010101010101010101010101010101010101010101010101'
>> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3. + 1000 -
>> 1000)))[0])
>> '0b1011111111110101010101010101010101010101010101010101011000000000'
>> --> -4/3. + 1000 - 1000
>> -1.3333333333333712
>>
>> The result of the last example can vary depending on the compiler
>> and optimization flags, whether the code runs on the main FPU or
>> vector coprocessor (eg, MMX), level of IEEE-754 compliance (which
>> varies from none for early Crays to partly for early NVIDIA GPUs to
>> full for most modern desktops), and any non-standard options (eg,
>> rounding mode and denormal truncation) which other parts of your
>> application or supporting libraries may have set...
>>
>>
>> Hope that helps.
>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>

From looiebwv at gmail.com  Tue Dec 10 16:31:49 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Tue, 10 Dec 2013 10:31:49 -0500
Subject: [CentralOH] Better Problem Description.
In-Reply-To: <CAChFk2Y2kGKqzPrFcUKWYhBQZ8mJr=RK7bsxC1nSB-ysCQEKGQ@mail.gmail.com>
References: <CACLJ_dE58juo6FvJ3KXPzc094ZLy1RTGpqx3yHJ4EmJ_MbvoWg@mail.gmail.com>
 <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
 <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>
 <CAChFk2bV8Ho8xSGDsrEkTp6AERKeFmyaW9QRZeqkvrLS8h4abw@mail.gmail.com>
 <20131210082239.13d368cf.nludban@columbus.rr.com>
 <CAChFk2Y2kGKqzPrFcUKWYhBQZ8mJr=RK7bsxC1nSB-ysCQEKGQ@mail.gmail.com>
Message-ID: <CAChFk2bCo7GJTgcEsY18VFDUG6Cio-sY3WW7ieNUcBH4RRTcZA@mail.gmail.com>

Oops:
The third paragraph should read:
In like manner, IF THE RIGHT HAND DIGIT IS <3,


On Tue, Dec 10, 2013 at 10:24 AM, Louis Bogdan <looiebwv at gmail.com> wrote:

> It seems that I'm having a problem in getting my point across as to what I
> would like to do, so let's try another approach.
>
> I have a number, 1.2348 and it is of no consequence or interest where it
> came from, etc.  I would like to manipulate the right hand most digit so
> that if it is greater that 7, I would increment it by 2 to 0 and end up
> with the number being either 1.2350 or 1.2351.
>
> In like manner I would just change the right hand most digit to 0 as this
> would have no effect on any other digits, I would end up with the number
> being 1.2340.
>
> Now if the right hand digit was not greater than 7 nor less than 3, it
> fall into the range of 3-8 and digits 3, 4, 5 ,6 &7 I change to digit 5
>
> The end result of the above I will have a number whose right hand digit
> will be either  0 or 5.  And here again, what happens next is of no
> consequence or interest to anyone but me.  But to satisfy some people's
> curiosity, the above number was derived from a keypad input, two integer
> four decimal, and manipulated by an internal equation.  The finally derived
> number will then manipulated into an integer which will the number of steps
> required to make a linear movement equal to the above number of inches.
>
> NOW!! HOW DO I SAY THAT IN PYTHON?
>
>
>
>
> On Tue, Dec 10, 2013 at 8:22 AM, Neil Ludban <nludban at columbus.rr.com>wrote:
>
>> On Mon, 9 Dec 2013 18:59:01 -0500
>> Louis Bogdan <looiebwv at gmail.com> wrote:
>> ...
>> > > On Mon, Dec 9, 2013 at 12:56 PM, Louis Bogdan <looiebwv at gmail.com>
>> wrote:
>> > >> Now I know that Python does rounding which I don't understand and
>> have
>> > >> not found any decent, understandable explanation how it does it.  I
>> > >> understand rounding, even way back when I was proficient with the
>> abacus.
>>
>> It's really quantization errors, not rounding.  If binary integers
>> are expressed as a sum of numbers from the set {1, 2, 4, 8, 16, ...}
>> then binary floating point numbers (from a very simplistic viewpoint)
>> add to that set the fractions {1/2, 1/4, 1/8, 1/16, ...}.  64-bit
>> doubles (the typical Python "float" type) enables 53 consecutive
>> values from that combined set:
>>
>> http://en.wikipedia.org/wiki/Double_precision_floating-point_format
>>
>> So numbers like 1, 1+1/2, 1+1/4, 1+1/8, can be represented exactly
>> in decimal and binary (the minus sign is added here to force the
>> bin function to output all 64 bits):
>>
>> --> import struct
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.0000')))[0])
>> '0b1011111111110000000000000000000000000000000000000000000000000000'
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.5000')))[0])
>> '0b1011111111111000000000000000000000000000000000000000000000000000'
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.2500')))[0])
>> '0b1011111111110100000000000000000000000000000000000000000000000000'
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.1250')))[0])
>> '0b1011111111110010000000000000000000000000000000000000000000000000'
>>
>>
>> 1+1/10 works in decimal, but is a repeating pattern in binary:
>> --> bin(struct.unpack('Q', struct.pack('d', float('-1.1000')))[0])
>> '0b1011111111110001100110011001100110011001100110011001100110011010'
>>
>>
>> 1+1/3 repeats in both decimal and binary:
>> --> -4/3.
>> -1.3333333333333333
>> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3.)))[0])
>> '0b1011111111110101010101010101010101010101010101010101010101010101'
>>
>>
>> And then there's the weird stuff that may concern you:
>>
>> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3. * 1000 /
>> 1000)))[0])
>> '0b1011111111110101010101010101010101010101010101010101010101010101'
>> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3. + 1000 -
>> 1000)))[0])
>> '0b1011111111110101010101010101010101010101010101010101011000000000'
>> --> -4/3. + 1000 - 1000
>> -1.3333333333333712
>>
>> The result of the last example can vary depending on the compiler
>> and optimization flags, whether the code runs on the main FPU or
>> vector coprocessor (eg, MMX), level of IEEE-754 compliance (which
>> varies from none for early Crays to partly for early NVIDIA GPUs to
>> full for most modern desktops), and any non-standard options (eg,
>> rounding mode and denormal truncation) which other parts of your
>> application or supporting libraries may have set...
>>
>>
>> Hope that helps.
>>
>
>
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From jep200404 at columbus.rr.com  Tue Dec 10 17:12:07 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 10 Dec 2013 11:12:07 -0500
Subject: [CentralOH] Accept The Solutions
In-Reply-To: <CAChFk2Y2kGKqzPrFcUKWYhBQZ8mJr=RK7bsxC1nSB-ysCQEKGQ@mail.gmail.com>
References: <CACLJ_dE58juo6FvJ3KXPzc094ZLy1RTGpqx3yHJ4EmJ_MbvoWg@mail.gmail.com>
 <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
 <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>
 <CAChFk2bV8Ho8xSGDsrEkTp6AERKeFmyaW9QRZeqkvrLS8h4abw@mail.gmail.com>
 <20131210082239.13d368cf.nludban@columbus.rr.com>
 <CAChFk2Y2kGKqzPrFcUKWYhBQZ8mJr=RK7bsxC1nSB-ysCQEKGQ@mail.gmail.com>
Message-ID: <20131210111207.6fd8d134.jep200404@columbus.rr.com>

On Tue, 10 Dec 2013 10:24:08 -0500, Louis Bogdan <looiebwv at gmail.com> wrote:

> It seems that I'm having a problem in getting my point across as to what I
> would like to do, ...

Lou, your problem has been understood and solved. 

See goo() near bottom in https://mail.python.org/pipermail/centraloh/2013-December/001919.html
as discussed in https://mail.python.org/pipermail/centraloh/2013-December/001937.html.
See custom_round() in https://mail.python.org/pipermail/centraloh/2013-December/001914.html.

From looiebwv at gmail.com  Tue Dec 10 17:16:26 2013
From: looiebwv at gmail.com (Louis Bogdan)
Date: Tue, 10 Dec 2013 11:16:26 -0500
Subject: [CentralOH] Better Problem Description.
In-Reply-To: <CAOxvq7z_P7TOCThfSTOL8xi4iZo=rx2YjAGKxw3sUEU9n4EcGg@mail.gmail.com>
References: <CACLJ_dE58juo6FvJ3KXPzc094ZLy1RTGpqx3yHJ4EmJ_MbvoWg@mail.gmail.com>
 <CAChFk2Y+kAPDJW=sX5Ymb3wHRmJtMhG70-p-+y9M46HbFXT5sg@mail.gmail.com>
 <CACLJ_dEqc4==fX8f1eOL8tFofenLONYHwNYgvRLn1KytSosP+w@mail.gmail.com>
 <CAChFk2bV8Ho8xSGDsrEkTp6AERKeFmyaW9QRZeqkvrLS8h4abw@mail.gmail.com>
 <20131210082239.13d368cf.nludban@columbus.rr.com>
 <CAChFk2Y2kGKqzPrFcUKWYhBQZ8mJr=RK7bsxC1nSB-ysCQEKGQ@mail.gmail.com>
 <CAOxvq7z_P7TOCThfSTOL8xi4iZo=rx2YjAGKxw3sUEU9n4EcGg@mail.gmail.com>
Message-ID: <CAChFk2bGqGUKKF2fRopk=GQYutd9tCt-DYKY+=61c11Ppd48TA@mail.gmail.com>

Almost, pertneer, just a little tweeking.

I think it should read

if last _digit <3                # this takes care of a 1 or 2
    last_digit=0
elif last_digit >7              # this takes care of an 8 or 9
    last_digit = 0
    next_last _digit +=1
else last_digit_<8          # this takes care of everything else
    last_digit + 5

I think the "everything else" should be last and also if last digit is
already 0, don't mess with it.

I guess if you put it in simple terms, it's easy to understand.  Thanks
much!!! lou


On Tue, Dec 10, 2013 at 10:31 AM, Joe Shaw <joe at joeshaw.org> wrote:

> Hi,
>
> To put it into pseudocode:
>
> if last_digit < 3:
>     last_digit = 0
> elif last_digit < 8:
>     last_digit = 5
> else:
>     last_digit = 0
>     next_to_last_digit += 1
>
> Is that correct?
>
> On Tue, Dec 10, 2013 at 10:24 AM, Louis Bogdan <looiebwv at gmail.com> wrote:
> > It seems that I'm having a problem in getting my point across as to what
> I
> > would like to do, so let's try another approach.
> >
> > I have a number, 1.2348 and it is of no consequence or interest where it
> > came from, etc.  I would like to manipulate the right hand most digit so
> > that if it is greater that 7, I would increment it by 2 to 0 and end up
> with
> > the number being either 1.2350 or 1.2351.
> >
> > In like manner I would just change the right hand most digit to 0 as this
> > would have no effect on any other digits, I would end up with the number
> > being 1.2340.
> >
> > Now if the right hand digit was not greater than 7 nor less than 3, it
> fall
> > into the range of 3-8 and digits 3, 4, 5 ,6 &7 I change to digit 5
> >
> > The end result of the above I will have a number whose right hand digit
> will
> > be either  0 or 5.  And here again, what happens next is of no
> consequence
> > or interest to anyone but me.  But to satisfy some people's curiosity,
> the
> > above number was derived from a keypad input, two integer four decimal,
> and
> > manipulated by an internal equation.  The finally derived number will
> then
> > manipulated into an integer which will the number of steps required to
> make
> > a linear movement equal to the above number of inches.
> >
> > NOW!! HOW DO I SAY THAT IN PYTHON?
> >
> >
> >
> >
> > On Tue, Dec 10, 2013 at 8:22 AM, Neil Ludban <nludban at columbus.rr.com>
> > wrote:
> >>
> >> On Mon, 9 Dec 2013 18:59:01 -0500
> >> Louis Bogdan <looiebwv at gmail.com> wrote:
> >> ...
> >> > > On Mon, Dec 9, 2013 at 12:56 PM, Louis Bogdan <looiebwv at gmail.com>
> >> > > wrote:
> >> > >> Now I know that Python does rounding which I don't understand and
> >> > >> have
> >> > >> not found any decent, understandable explanation how it does it.  I
> >> > >> understand rounding, even way back when I was proficient with the
> >> > >> abacus.
> >>
> >> It's really quantization errors, not rounding.  If binary integers
> >> are expressed as a sum of numbers from the set {1, 2, 4, 8, 16, ...}
> >> then binary floating point numbers (from a very simplistic viewpoint)
> >> add to that set the fractions {1/2, 1/4, 1/8, 1/16, ...}.  64-bit
> >> doubles (the typical Python "float" type) enables 53 consecutive
> >> values from that combined set:
> >>
> >> http://en.wikipedia.org/wiki/Double_precision_floating-point_format
> >>
> >> So numbers like 1, 1+1/2, 1+1/4, 1+1/8, can be represented exactly
> >> in decimal and binary (the minus sign is added here to force the
> >> bin function to output all 64 bits):
> >>
> >> --> import struct
> >> --> bin(struct.unpack('Q', struct.pack('d', float('-1.0000')))[0])
> >> '0b1011111111110000000000000000000000000000000000000000000000000000'
> >> --> bin(struct.unpack('Q', struct.pack('d', float('-1.5000')))[0])
> >> '0b1011111111111000000000000000000000000000000000000000000000000000'
> >> --> bin(struct.unpack('Q', struct.pack('d', float('-1.2500')))[0])
> >> '0b1011111111110100000000000000000000000000000000000000000000000000'
> >> --> bin(struct.unpack('Q', struct.pack('d', float('-1.1250')))[0])
> >> '0b1011111111110010000000000000000000000000000000000000000000000000'
> >>
> >>
> >> 1+1/10 works in decimal, but is a repeating pattern in binary:
> >> --> bin(struct.unpack('Q', struct.pack('d', float('-1.1000')))[0])
> >> '0b1011111111110001100110011001100110011001100110011001100110011010'
> >>
> >>
> >> 1+1/3 repeats in both decimal and binary:
> >> --> -4/3.
> >> -1.3333333333333333
> >> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3.)))[0])
> >> '0b1011111111110101010101010101010101010101010101010101010101010101'
> >>
> >>
> >> And then there's the weird stuff that may concern you:
> >>
> >> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3. * 1000 /
> >> 1000)))[0])
> >> '0b1011111111110101010101010101010101010101010101010101010101010101'
> >> --> bin(struct.unpack('Q', struct.pack('d', float(-4/3. + 1000 -
> >> 1000)))[0])
> >> '0b1011111111110101010101010101010101010101010101010101011000000000'
> >> --> -4/3. + 1000 - 1000
> >> -1.3333333333333712
> >>
> >> The result of the last example can vary depending on the compiler
> >> and optimization flags, whether the code runs on the main FPU or
> >> vector coprocessor (eg, MMX), level of IEEE-754 compliance (which
> >> varies from none for early Crays to partly for early NVIDIA GPUs to
> >> full for most modern desktops), and any non-standard options (eg,
> >> rounding mode and denormal truncation) which other parts of your
> >> application or supporting libraries may have set...
> >>
> >>
> >> Hope that helps.
> >
> >
> >
> > _______________________________________________
> > CentralOH mailing list
> > CentralOH at python.org
> > https://mail.python.org/mailman/listinfo/centraloh
> >
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
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From jep200404 at columbus.rr.com  Tue Dec 10 22:57:30 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 10 Dec 2013 16:57:30 -0500
Subject: [CentralOH] =?utf-8?q?2013-12-09_=E6=9C=83=E8=AD=B0_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8=?=
Message-ID: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>

Thanks to Pillar Technology, Bob Myers, Nate Bennick, 
and Ben Rogers for hosting us. They took good care of us. 
There was salad, cookies including cream filled soft sandwich 
pumpkin cookies, plenty of pizza and adult beverages. 

http://www.catb.org/~esr/faqs/smart-questions.html#goal

    Often, people who need technical help have a high-level goal 
    in mind and get stuck on what they think is one particular 
    path towards the goal. They come for help with the step, 
    but don't realize that the path is wrong. 
    It can take substantial effort to get past this.

http://en.wikipedia.org/wiki/Socratic_questioning
http://en.wikipedia.org/wiki/Socratic_method
http://www.catb.org/~esr/faqs/smart-questions.html
http://wiki.centos.org/SpoonFeed
http://web.archive.org/web/20090627155454/www.greenend.org.uk/rjk/2000/06/14/quoting.html

We were in a new room where the projector shined on a bare wall. 
Because the room lights could be turned off to not shine on the 
wall, it was easy to see. 

Eric Floehr
Computer Vision
Open-Source Computer Vision Library
written in C(++)
python library that interfaces with it. (pretty thin layer)
sudo apt-get install python-opencv
SimpleCV

See poll on:
http://www.autoweek.com/article/20130530/CARNEWS/130539990

low-level nittygritty detail Practical Computer Vision
    opencv is introduced p197
Practical Computer Vision with SimpleCV 
The Simple Way to Make Technology See 
By Kurt Demaagd, Anthony Oliver, Nathan Oostendorp, Katherine Scott
Publisher: O'Reilly Media
Released: July 2012
Pages: 254
http://shop.oreilly.com/product/0636920024057.do

OpenCV Computing with Python

Programming Computer Vision with Python 
Tools and algorithms for analyzing images 
By Jan Erik Solem
Publisher: O'Reilly Media
Released: June 2012
Pages: 264
http://shop.oreilly.com/product/0636920022923.do
    OpenCV is in active development, so differences from book have arisen.

https://github.com/sightmachine/simplecv

Eric likes to use virtualenv wrapper
    https://pypi.python.org/pypi/virtualenvwrapper
Eric likes to install big packages (like scipy and numpy) 
from system package manager (apt-get/yum)
mkvirtualenv --system-site-packages cohpy-dec2013
workon <name of virtual environment>
    tab completion works

pip install svgwrite # undocumented dependency

simplecv has a shell
    looks like its built on top of ipython (not notebook)

SimpleCV:1> help(Motion)
SimpleCV:2> example 32

sudoku solver
github.com/abidrahmank/OpenCV2-Python/tree/master/OpenCV*?
https://github.com/abidrahmank/OpenCV2-Python/tree/master/OpenCV_Python_Blog/sudoku_v_0.0.6

augmented reality

OpenCV Computer Vision with Python 
By Joseph Howse
Publisher: Packt Publishing
Released: April 2013
Pages: 122
http://shop.oreilly.com/product/9781782163923.do

Learning OpenCV 
Computer Vision with the OpenCV Library 
By Gary Bradski, Adrian Kaehler
Publisher: O'Reilly Media
Released: September 2008
Pages: 580
http://shop.oreilly.com/product/9780596516130.do

Learning OpenCV 
Computer Vision in C++ with the OpenCV Library 
By Adrian Kaehler, Gary Bradski
Publisher: O'Reilly Media
Released: October 2013
Pages: 575
http://shop.oreilly.com/product/0636920022497.do

Use pillow instead of PIL, because PIL has stagnated.
https://pypi.python.org/pypi/Pillow
https://pypi.python.org/pypi/Pillow/2.2.1
runs on Python 3
https://pypi.python.org/pypi/requests
https://github.com/profjrr/COhPyDec92013

James Reed
gave presentation on web page scraping with Python
using BeautifulSoup
from bs4 import BeautifulSoup
spashtop remote desktop
wp:Splashtop#Splashtop_Remote_Desktop
https://pypi.python.org/pypi/Scrapy

The Explorers Club was closed, even though we were there during posted hours.
http://www.explorersclubmv.com/
There seems to be no apostrophes in "Explorers Club".
Went to Jimmy V's instead. Gyro & fries for $5.
http://www.jimmyvspub.com/
912 S High St

Lorem Ipsum left some comments.
http://www.jimmyvspub.com/comments.html

Someone kept asking how to write SQL when using an ORM,
so a presentation on the benefits of using an ORM is needed.

maybe http://www.linkedin.com/pub/john-cassidy/8/B21/26A
http://www.yelp.com/biz/cgi-columbus-2
http://www.cgi.com/en
http://www.superpages.com/bp/Columbus-OH/CGI-L2051932011.htm
http://www.cgi.com/en/ohio

what about pip install at system level?
    is that inherited?
        with --system-site-packages?
        with --no-site-packages?

From winningham at gmail.com  Tue Dec 10 23:09:26 2013
From: winningham at gmail.com (Thomas Winningham)
Date: Tue, 10 Dec 2013 17:09:26 -0500
Subject: [CentralOH] =?utf-8?q?2013-12-09_=E6=9C=83=E8=AD=B0_Scribbles_?=
	=?utf-8?b?76SY5pu4L+aDoeaWhz8=?=
In-Reply-To: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
References: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
Message-ID: <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>

Wanted to mention in relation the first link or so, the Perl people talk
about the XY problem:
http://www.perlmonks.org/index.pl?node_id=542341 ... I know this tripped me
up early in my programming efforts, but I think even now I do this with new
things I'm exploring. The worst was when the web was a little smaller and
the only things you'd find were your own posts asking the unanswered
question.

Also, SimpleCV is amazingly fun to work with, thank you for giving that
library some air time!!

Is lxml or pyquery what should be talked about instead of beautiful soup? i
know lxml has a beautiful soup mode, but CSS3 selectors are so very nice.

Thank you guys for making such a great list!!


On Tue, Dec 10, 2013 at 4:57 PM, <jep200404 at columbus.rr.com> wrote:

> Thanks to Pillar Technology, Bob Myers, Nate Bennick,
> and Ben Rogers for hosting us. They took good care of us.
> There was salad, cookies including cream filled soft sandwich
> pumpkin cookies, plenty of pizza and adult beverages.
>
> http://www.catb.org/~esr/faqs/smart-questions.html#goal
>
>     Often, people who need technical help have a high-level goal
>     in mind and get stuck on what they think is one particular
>     path towards the goal. They come for help with the step,
>     but don't realize that the path is wrong.
>     It can take substantial effort to get past this.
>
> http://en.wikipedia.org/wiki/Socratic_questioning
> http://en.wikipedia.org/wiki/Socratic_method
> http://www.catb.org/~esr/faqs/smart-questions.html
> http://wiki.centos.org/SpoonFeed
>
> http://web.archive.org/web/20090627155454/www.greenend.org.uk/rjk/2000/06/14/quoting.html
>
> We were in a new room where the projector shined on a bare wall.
> Because the room lights could be turned off to not shine on the
> wall, it was easy to see.
>
> Eric Floehr
> Computer Vision
> Open-Source Computer Vision Library
> written in C(++)
> python library that interfaces with it. (pretty thin layer)
> sudo apt-get install python-opencv
> SimpleCV
>
> See poll on:
> http://www.autoweek.com/article/20130530/CARNEWS/130539990
>
> low-level nittygritty detail Practical Computer Vision
>     opencv is introduced p197
> Practical Computer Vision with SimpleCV
> The Simple Way to Make Technology See
> By Kurt Demaagd, Anthony Oliver, Nathan Oostendorp, Katherine Scott
> Publisher: O'Reilly Media
> Released: July 2012
> Pages: 254
> http://shop.oreilly.com/product/0636920024057.do
>
> OpenCV Computing with Python
>
> Programming Computer Vision with Python
> Tools and algorithms for analyzing images
> By Jan Erik Solem
> Publisher: O'Reilly Media
> Released: June 2012
> Pages: 264
> http://shop.oreilly.com/product/0636920022923.do
>     OpenCV is in active development, so differences from book have arisen.
>
> https://github.com/sightmachine/simplecv
>
> Eric likes to use virtualenv wrapper
>     https://pypi.python.org/pypi/virtualenvwrapper
> Eric likes to install big packages (like scipy and numpy)
> from system package manager (apt-get/yum)
> mkvirtualenv --system-site-packages cohpy-dec2013
> workon <name of virtual environment>
>     tab completion works
>
> pip install svgwrite # undocumented dependency
>
> simplecv has a shell
>     looks like its built on top of ipython (not notebook)
>
> SimpleCV:1> help(Motion)
> SimpleCV:2> example 32
>
> sudoku solver
> github.com/abidrahmank/OpenCV2-Python/tree/master/OpenCV*?
>
> https://github.com/abidrahmank/OpenCV2-Python/tree/master/OpenCV_Python_Blog/sudoku_v_0.0.6
>
> augmented reality
>
> OpenCV Computer Vision with Python
> By Joseph Howse
> Publisher: Packt Publishing
> Released: April 2013
> Pages: 122
> http://shop.oreilly.com/product/9781782163923.do
>
> Learning OpenCV
> Computer Vision with the OpenCV Library
> By Gary Bradski, Adrian Kaehler
> Publisher: O'Reilly Media
> Released: September 2008
> Pages: 580
> http://shop.oreilly.com/product/9780596516130.do
>
> Learning OpenCV
> Computer Vision in C++ with the OpenCV Library
> By Adrian Kaehler, Gary Bradski
> Publisher: O'Reilly Media
> Released: October 2013
> Pages: 575
> http://shop.oreilly.com/product/0636920022497.do
>
> Use pillow instead of PIL, because PIL has stagnated.
> https://pypi.python.org/pypi/Pillow
> https://pypi.python.org/pypi/Pillow/2.2.1
> runs on Python 3
> https://pypi.python.org/pypi/requests
> https://github.com/profjrr/COhPyDec92013
>
> James Reed
> gave presentation on web page scraping with Python
> using BeautifulSoup
> from bs4 import BeautifulSoup
> spashtop remote desktop
> wp:Splashtop#Splashtop_Remote_Desktop
> https://pypi.python.org/pypi/Scrapy
>
> The Explorers Club was closed, even though we were there during posted
> hours.
> http://www.explorersclubmv.com/
> There seems to be no apostrophes in "Explorers Club".
> Went to Jimmy V's instead. Gyro & fries for $5.
> http://www.jimmyvspub.com/
> 912 S High St
>
> Lorem Ipsum left some comments.
> http://www.jimmyvspub.com/comments.html
>
> Someone kept asking how to write SQL when using an ORM,
> so a presentation on the benefits of using an ORM is needed.
>
> maybe http://www.linkedin.com/pub/john-cassidy/8/B21/26A
> http://www.yelp.com/biz/cgi-columbus-2
> http://www.cgi.com/en
> http://www.superpages.com/bp/Columbus-OH/CGI-L2051932011.htm
> http://www.cgi.com/en/ohio
>
> what about pip install at system level?
>     is that inherited?
>         with --system-site-packages?
>         with --no-site-packages?
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
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From jep200404 at columbus.rr.com  Tue Dec 10 23:37:03 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Tue, 10 Dec 2013 17:37:03 -0500
Subject: [CentralOH] Screen Scraping Presentation
In-Reply-To: <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
References: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
 <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
Message-ID: <20131210173703.55105ff2.jep200404@columbus.rr.com>

On Tue, 10 Dec 2013 17:09:26 -0500, Thomas Winningham <winningham at gmail.com> wrote:

> Is lxml or pyquery what should be talked about instead of beautiful soup? i
> know lxml has a beautiful soup mode, but CSS3 selectors are so very nice.

Please give a presentation on other ways of screen scraping 
(that might even be better). 

How many other folks would like to see his presentation? 


From jcfolsom at pureperfect.com  Tue Dec 10 23:45:48 2013
From: jcfolsom at pureperfect.com (Chris Folsom)
Date: Tue, 10 Dec 2013 15:45:48 -0700
Subject: [CentralOH] Screen Scraping Presentation
Message-ID: <20131210154548.7098ff60d8000ac98b0356cd27c73871.a143489087.wbe@email04.secureserver.net>

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From miller.eric.t at gmail.com  Tue Dec 10 23:50:52 2013
From: miller.eric.t at gmail.com (Eric Miller)
Date: Tue, 10 Dec 2013 17:50:52 -0500
Subject: [CentralOH] Screen Scraping Presentation
In-Reply-To: <20131210154548.7098ff60d8000ac98b0356cd27c73871.a143489087.wbe@email04.secureserver.net>
References: <20131210154548.7098ff60d8000ac98b0356cd27c73871.a143489087.wbe@email04.secureserver.net>
Message-ID: <CAN67YM41+E2QXwtC4PJyWFM0OC4SSzzXXwHn_JPO0RLQ7FCi=A@mail.gmail.com>

+1, would love to see this.


On Tue, Dec 10, 2013 at 5:45 PM, Chris Folsom <jcfolsom at pureperfect.com>wrote:

>
> Sounds awesome. I would definitely attend. Currently using Nutch + Regexp.
>
>  -------- Original Message --------
> Subject: [CentralOH] Screen Scraping Presentation
> From: jep200404 at columbus.rr.com
> Date: Tue, December 10, 2013 5:37 pm
> To: "Mailing list for Central Ohio Python User Group (COhPy)"
> <centraloh at python.org>
>
> On Tue, 10 Dec 2013 17:09:26 -0500, Thomas Winningham <
> winningham at gmail.com> wrote:
>
> > Is lxml or pyquery what should be talked about instead of beautiful
> soup? i
> > know lxml has a beautiful soup mode, but CSS3 selectors are so very nice.
>
> Please give a presentation on other ways of screen scraping
> (that might even be better).
>
> How many other folks would like to see his presentation?
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From winningham at gmail.com  Tue Dec 10 23:56:38 2013
From: winningham at gmail.com (Thomas Winningham)
Date: Tue, 10 Dec 2013 17:56:38 -0500
Subject: [CentralOH] Screen Scraping Presentation
In-Reply-To: <CAN67YM41+E2QXwtC4PJyWFM0OC4SSzzXXwHn_JPO0RLQ7FCi=A@mail.gmail.com>
References: <20131210154548.7098ff60d8000ac98b0356cd27c73871.a143489087.wbe@email04.secureserver.net>
 <CAN67YM41+E2QXwtC4PJyWFM0OC4SSzzXXwHn_JPO0RLQ7FCi=A@mail.gmail.com>
Message-ID: <CAJShLf9N3oZgDLV86NeTEw6QiNeoL9XJ+EwswWTbys+pm4Z_tg@mail.gmail.com>

Oh geez now I've done it :P

Honestly I don't do too much. I had only heard about Nutch once, and when I
googled it came across Scrapy. I did have some success with PyQuery like
earlier in the year, but I only needed like one thing really and was
thinking about the problem in CSS3 style, so it fit. I cannot say much
about its performance. I've used lxml for some broken HTML and XML since
its forgiving parser is somewhat nice depending on how muddy the water the
is, but I don't know how much I could say about these things you couldn't
google.

I'll play around and try to come up with something then perhaps heh :P


On Tue, Dec 10, 2013 at 5:50 PM, Eric Miller <miller.eric.t at gmail.com>wrote:

> +1, would love to see this.
>
>
> On Tue, Dec 10, 2013 at 5:45 PM, Chris Folsom <jcfolsom at pureperfect.com>wrote:
>
>>
>> Sounds awesome. I would definitely attend. Currently using Nutch + Regexp.
>>
>>  -------- Original Message --------
>> Subject: [CentralOH] Screen Scraping Presentation
>> From: jep200404 at columbus.rr.com
>> Date: Tue, December 10, 2013 5:37 pm
>> To: "Mailing list for Central Ohio Python User Group (COhPy)"
>> <centraloh at python.org>
>>
>> On Tue, 10 Dec 2013 17:09:26 -0500, Thomas Winningham <
>> winningham at gmail.com> wrote:
>>
>> > Is lxml or pyquery what should be talked about instead of beautiful
>> soup? i
>> > know lxml has a beautiful soup mode, but CSS3 selectors are so very
>> nice.
>>
>> Please give a presentation on other ways of screen scraping
>> (that might even be better).
>>
>> How many other folks would like to see his presentation?
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From herrold at owlriver.com  Tue Dec 10 23:51:16 2013
From: herrold at owlriver.com (R P Herrold)
Date: Tue, 10 Dec 2013 17:51:16 -0500 (EST)
Subject: [CentralOH] Screen Scraping Presentation
In-Reply-To: <20131210173703.55105ff2.jep200404@columbus.rr.com>
References: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
 <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
 <20131210173703.55105ff2.jep200404@columbus.rr.com>
Message-ID: <alpine.LRH.2.03.1312101748410.2268@bjyevire.pbz>

On Tue, 10 Dec 2013, jep200404 at columbus.rr.com wrote:

> On Tue, 10 Dec 2013 17:09:26 -0500, Thomas Winningham <winningham at gmail.com> wrote:
> 
> > Is lxml or pyquery what should be talked about instead of beautiful soup? i
> > know lxml has a beautiful soup mode, but CSS3 selectors are so very nice.
> 
> Please give a presentation on other ways of screen scraping 
> (that might even be better). 

I was thinking that an optically based OpenCV and the 
online-poker venues seemed like a natural fit (compared to the 
bloodless Soduku).  The operators of those sites use clients 
that try to keep away robo-players ... but ... if one can work 
across an air-gap, they wil not be able to stop that

-- Russ herrold

From winningham at gmail.com  Wed Dec 11 00:25:51 2013
From: winningham at gmail.com (Thomas Winningham)
Date: Tue, 10 Dec 2013 18:25:51 -0500
Subject: [CentralOH] Screen Scraping Presentation
In-Reply-To: <alpine.LRH.2.03.1312101748410.2268@bjyevire.pbz>
References: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
 <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
 <20131210173703.55105ff2.jep200404@columbus.rr.com>
 <alpine.LRH.2.03.1312101748410.2268@bjyevire.pbz>
Message-ID: <CAJShLf_kv9DNRfMuhEcBK9LpzKhoPz6=He4pm7HgrqEEd8ifPQ@mail.gmail.com>

I would check out Sikuli for that, very interesting Jython thing where you
put little clips of the screen as parameters to functions.

But couldn't they eventually tell by the too precise timing? Then maybe you
could come up with a bunch of fake human things like triple thinking,
making occasional dumb mistakes, maybe record your nervous mouse habits and
replay them... hrmm!  I'm too busy gambling with my career and
inter-personal relationships which is enough money down the drain as it is
:P Could be fun to play with!! What about short of full automation some
kind of tooling to let you play like hundreds of hands simultaneously
somehow better? Or some such assistance that is still technically not a
robot?


On Tue, Dec 10, 2013 at 5:51 PM, R P Herrold <herrold at owlriver.com> wrote:

> On Tue, 10 Dec 2013, jep200404 at columbus.rr.com wrote:
>
> > On Tue, 10 Dec 2013 17:09:26 -0500, Thomas Winningham <
> winningham at gmail.com> wrote:
> >
> > > Is lxml or pyquery what should be talked about instead of beautiful
> soup? i
> > > know lxml has a beautiful soup mode, but CSS3 selectors are so very
> nice.
> >
> > Please give a presentation on other ways of screen scraping
> > (that might even be better).
>
> I was thinking that an optically based OpenCV and the
> online-poker venues seemed like a natural fit (compared to the
> bloodless Soduku).  The operators of those sites use clients
> that try to keep away robo-players ... but ... if one can work
> across an air-gap, they wil not be able to stop that
>
> -- Russ herrold
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
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From herrold at owlriver.com  Wed Dec 11 00:38:50 2013
From: herrold at owlriver.com (R P Herrold)
Date: Tue, 10 Dec 2013 18:38:50 -0500 (EST)
Subject: [CentralOH] Screen Scraping Presentation
In-Reply-To: <CAJShLf_kv9DNRfMuhEcBK9LpzKhoPz6=He4pm7HgrqEEd8ifPQ@mail.gmail.com>
References: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
 <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
 <20131210173703.55105ff2.jep200404@columbus.rr.com>
 <alpine.LRH.2.03.1312101748410.2268@bjyevire.pbz>
 <CAJShLf_kv9DNRfMuhEcBK9LpzKhoPz6=He4pm7HgrqEEd8ifPQ@mail.gmail.com>
Message-ID: <alpine.LRH.2.03.1312101832390.2268@bjyevire.pbz>

On Tue, 10 Dec 2013, Thomas Winningham wrote:

> I would check out Sikuli for that, very interesting Jython thing where you
> put little clips of the screen as parameters to functions.
 
> But couldn't they eventually tell by the too precise timing? 

easy enough to add several non-correlated 'jitter' delays ... 
and poker is not a 'speed' game, so one need not be fast

> Then maybe you
> could come up with a bunch of fake human things like triple thinking,
> making occasional dumb mistakes, maybe record your nervous mouse habits and
> replay them... hrmm! 

yes ... called bluffing in some circles  ;)

> I'm too busy gambling with my career and
> inter-personal relationships which is enough money down the drain as it is
> :P Could be fun to play with!! What about short of full automation some
> kind of tooling to let you play like hundreds of hands simultaneously
> somehow better? 

One assumes that the vendors watch for IP addresses of players 
to rule out such economies of scale

> Or some such assistance that is still technically not a
> robot?

a 'heads up display' overlay to assist a live player to peak 
performance, and to also act as a trainer of 'correct' 
repsonses, comes to mind:  
	Cue: Nicholas Cage, singing 'I am the greatest'
		https://www.youtube.com/watch?v=2FyuHA_zAOM

-- Russ herrold

From eric at intellovations.com  Wed Dec 11 00:41:11 2013
From: eric at intellovations.com (Eric Floehr)
Date: Tue, 10 Dec 2013 18:41:11 -0500
Subject: [CentralOH] Screen Scraping Presentation
In-Reply-To: <alpine.LRH.2.03.1312101832390.2268@bjyevire.pbz>
References: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
 <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
 <20131210173703.55105ff2.jep200404@columbus.rr.com>
 <alpine.LRH.2.03.1312101748410.2268@bjyevire.pbz>
 <CAJShLf_kv9DNRfMuhEcBK9LpzKhoPz6=He4pm7HgrqEEd8ifPQ@mail.gmail.com>
 <alpine.LRH.2.03.1312101832390.2268@bjyevire.pbz>
Message-ID: <CAJzarMNaj5bi=9vYjASYqNRYJpu7nUseCo55CkMxOHV3HLPYOA@mail.gmail.com>

>
> a 'heads up display' overlay to assist a live player to peak
> performance, and to also act as a trainer of 'correct'
> repsonses, comes to mind:
>

There's an app for that (on Android at least) and it uses OpenCV even!

https://play.google.com/store/apps/details?id=net.aasuited.pokeroddscamera

-Eric
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From eric at intellovations.com  Tue Dec 10 20:03:12 2013
From: eric at intellovations.com (Eric Floehr)
Date: Tue, 10 Dec 2013 14:03:12 -0500
Subject: [CentralOH] The Mustached Cloud
Message-ID: <CAJzarMP3SzefHys6nuE4A4tPSNPyzofV4G4Wjkjn3A=5pPr7Aw@mail.gmail.com>

Enjoyed presenting last night, thanks to Pillar for hosting.

I'm still working on gathering all the links together, but I thought I'd
share a cool face found in one of my timelapses via SimpleCV...

I call him the Mustached Cloud Man. He looks better the more you squint.
The attached picture was enhanced a bit by stretching contrast,
despeckling, and normalizing.


[image: Inline image 1]
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From Richard.C.1 at bwc.state.oh.us  Wed Dec 11 13:57:24 2013
From: Richard.C.1 at bwc.state.oh.us (Richard.C.1 at bwc.state.oh.us)
Date: Wed, 11 Dec 2013 12:57:24 +0000
Subject: [CentralOH] Screen Scraping Presentation
In-Reply-To: <20131210173703.55105ff2.jep200404@columbus.rr.com>
References: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
 <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
 <20131210173703.55105ff2.jep200404@columbus.rr.com>
Message-ID: <05CEC79B81631F4BAFAF8E30F65E45DB0930B3EB@SOCEMMB04>

Yes.

-----Original Message-----
From: CentralOH [mailto:centraloh-bounces+richard.c.1=bwc.state.oh.us at python.org] On Behalf Of jep200404 at columbus.rr.com
Sent: Tuesday, December 10, 2013 5:37 PM
To: Mailing list for Central Ohio Python User Group (COhPy)
Subject: [CentralOH] Screen Scraping Presentation

On Tue, 10 Dec 2013 17:09:26 -0500, Thomas Winningham <winningham at gmail.com> wrote:

> Is lxml or pyquery what should be talked about instead of beautiful
> soup? i know lxml has a beautiful soup mode, but CSS3 selectors are so very nice.

Please give a presentation on other ways of screen scraping (that might even be better).

How many other folks would like to see his presentation?

_______________________________________________
CentralOH mailing list
CentralOH at python.org
https://mail.python.org/mailman/listinfo/centraloh

Portions of this message may be confidential under an exemption to Ohio's public records law or under a legal privilege. If you have received this message in error or due to an unauthorized transmission or interception, please delete all copies from your system without disclosing, copying, or transmitting this message.


From brian.costlow at gmail.com  Wed Dec 11 20:37:25 2013
From: brian.costlow at gmail.com (Brian Costlow)
Date: Wed, 11 Dec 2013 14:37:25 -0500
Subject: [CentralOH] The Mustached Cloud
In-Reply-To: <CAJzarMP3SzefHys6nuE4A4tPSNPyzofV4G4Wjkjn3A=5pPr7Aw@mail.gmail.com>
References: <CAJzarMP3SzefHys6nuE4A4tPSNPyzofV4G4Wjkjn3A=5pPr7Aw@mail.gmail.com>
Message-ID: <CACLJ_dGeENyqf3s_W+0TSN-KOqS73bgDO7YxyRLDVhiTa+8qmQ@mail.gmail.com>

If I squint real hard, I get this

http://images4.wikia.nocookie.net/__cb20130510203024/deadliestfiction/images/7/7e/Iosif_Stalin.jpeg


On Tue, Dec 10, 2013 at 2:03 PM, Eric Floehr <eric at intellovations.com>wrote:

> Enjoyed presenting last night, thanks to Pillar for hosting.
>
> I'm still working on gathering all the links together, but I thought I'd
> share a cool face found in one of my timelapses via SimpleCV...
>
> I call him the Mustached Cloud Man. He looks better the more you squint.
> The attached picture was enhanced a bit by stretching contrast,
> despeckling, and normalizing.
>
>
> [image: Inline image 1]
>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From jcfolsom at pureperfect.com  Thu Dec 12 04:34:05 2013
From: jcfolsom at pureperfect.com (Chris Folsom)
Date: Wed, 11 Dec 2013 20:34:05 -0700
Subject: [CentralOH] The Mustached Cloud
Message-ID: <20131211203405.7098ff60d8000ac98b0356cd27c73871.f936695649.wbe@email04.secureserver.net>

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From eric at intellovations.com  Thu Dec 12 14:19:47 2013
From: eric at intellovations.com (Eric Floehr)
Date: Thu, 12 Dec 2013 08:19:47 -0500
Subject: [CentralOH] Great example of IPython Notebook
Message-ID: <CAJzarMNKD012Kqz3u5Q1Du2oU8W6qz4jhd93Fmun49H6FbPoAw@mail.gmail.com>

A great example of the use of IPython Notebook, used to examine the online
reaction to Amazon Prime Air:

http://nbviewer.ipython.org/github/ptwobrussell/Mining-the-Social-Web-2nd-Edition/blob/master/ipynb/__Understanding%20the%20Reaction%20to%20%22Amazon%20Prime%20Air%22.ipynb
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From joe at joeshaw.org  Thu Dec 12 19:49:11 2013
From: joe at joeshaw.org (Joe Shaw)
Date: Thu, 12 Dec 2013 13:49:11 -0500
Subject: [CentralOH] Great example of IPython Notebook
In-Reply-To: <CAJzarMNKD012Kqz3u5Q1Du2oU8W6qz4jhd93Fmun49H6FbPoAw@mail.gmail.com>
References: <CAJzarMNKD012Kqz3u5Q1Du2oU8W6qz4jhd93Fmun49H6FbPoAw@mail.gmail.com>
Message-ID: <CAOxvq7ySNKEgTiwozUr=wJ-3caBVw_w1NTTrxyVinbTRPTkcWQ@mail.gmail.com>

Hi,

Another great example: Peter Norvig's examination of the traveling
salesman problem.

http://nbviewer.ipython.org/url/norvig.com/ipython/TSPv3.ipynb

Joe

On Thu, Dec 12, 2013 at 8:19 AM, Eric Floehr <eric at intellovations.com> wrote:
> A great example of the use of IPython Notebook, used to examine the online
> reaction to Amazon Prime Air:
>
> http://nbviewer.ipython.org/github/ptwobrussell/Mining-the-Social-Web-2nd-Edition/blob/master/ipynb/__Understanding%20the%20Reaction%20to%20%22Amazon%20Prime%20Air%22.ipynb
>
>
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>

From jaredbrock at sbcglobal.net  Sun Dec 15 22:53:37 2013
From: jaredbrock at sbcglobal.net (Jared Brock)
Date: Sun, 15 Dec 2013 13:53:37 -0800 (PST)
Subject: [CentralOH] Looking for Introductory Python Materials
Message-ID: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>

Greeting Pythonistas. I am a student with a neglegible amount of programming experience who was referred to both Python and this group as a way to learn the language. I am looking for suggestings on books, websites, or other materials that can serve as a good starting place. The one online tutorial I found (http://docs.python.org/2/tutorial/index.html) did have examples of basic concepts but lacked any suggested problems to solve to reinforce those concepts.
And in case someone asks, I am not currently able to make it to the Friday DoJo's for the time being.

Thanks for reading, and double thanks for replies.
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From miller.eric.t at gmail.com  Sun Dec 15 23:35:11 2013
From: miller.eric.t at gmail.com (Eric Miller)
Date: Sun, 15 Dec 2013 17:35:11 -0500
Subject: [CentralOH] Looking for Introductory Python Materials
In-Reply-To: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
References: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
Message-ID: <CAN67YM6thmOXus-dx8pV4L+6U5prJ5V0YLYHfCap08qg1vUZdg@mail.gmail.com>

If you want free, then these are good resources:

http://www.tutorialspoint.com/python/
http://www.learnpython.org/
https://developers.google.com/edu/python/
http://docs.python.org/2/tutorial/
and, my personal favorite:  http://pymotw.com/2/contents.html

If you aren't afraid of paying, the O'Reilly certification is second to
none.  I am halfway done with it, and it taught me a lot.  It's 160 hours
of training total, it can't be beat to get you from zero to hero in the
shortest amount of time.

If you are new to python, you may want to avoid python 3.3 in favor of 2.7.6

This might sound like weird advice, but 3.3 isn't really "better" from a
learning pespective.  So much of what is availalbe online and in
stackoverflow articles is written in 2.x.x, and 3.3. is not backwards
compatible.  Once you know python, switching to 3.3 is a breeze (or back
and forth between the two).  But for learning, I'd say use 2.7.6

http://www.oreillyschool.com/certificate-programs/python-programming/


On Sun, Dec 15, 2013 at 4:53 PM, Jared Brock <jaredbrock at sbcglobal.net>wrote:

> Greeting Pythonistas. I am a student with a neglegible amount of
> programming experience who was referred to both Python and this group as a
> way to learn the language. I am looking for suggestings on books, websites,
> or other materials that can serve as a good starting place. The one online
> tutorial I found (http://docs.python.org/2/tutorial/index.html) did have
> examples of basic concepts but lacked any suggested problems to solve to
> reinforce those concepts.
> And in case someone asks, I am not currently able to make it to the Friday
> DoJo's for the time being.
>
> Thanks for reading, and double thanks for replies.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From phpdotsql at gmail.com  Sun Dec 15 23:43:52 2013
From: phpdotsql at gmail.com (Brian Good)
Date: Sun, 15 Dec 2013 17:43:52 -0500
Subject: [CentralOH] Looking for Introductory Python Materials
In-Reply-To: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
References: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
Message-ID: <CANXALJWva-g94u_UKELA7ZQYU-gPxn11s8yMhXrmFC1DKw_T0Q@mail.gmail.com>

http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-189-a-gentle-introduction-to-programming-using-python-january-iap-2011/


On Sun, Dec 15, 2013 at 4:53 PM, Jared Brock <jaredbrock at sbcglobal.net>wrote:

> Greeting Pythonistas. I am a student with a neglegible amount of
> programming experience who was referred to both Python and this group as a
> way to learn the language. I am looking for suggestings on books, websites,
> or other materials that can serve as a good starting place. The one online
> tutorial I found (http://docs.python.org/2/tutorial/index.html) did have
> examples of basic concepts but lacked any suggested problems to solve to
> reinforce those concepts.
> And in case someone asks, I am not currently able to make it to the Friday
> DoJo's for the time being.
>
> Thanks for reading, and double thanks for replies.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From pcarswell.1 at gmail.com  Mon Dec 16 16:58:26 2013
From: pcarswell.1 at gmail.com (Peter Carswell)
Date: Mon, 16 Dec 2013 10:58:26 -0500
Subject: [CentralOH] Looking for Introductory Python Materials
In-Reply-To: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
References: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
Message-ID: <CAAZoxjoVdw=n3X5FMd4VTc6SDoN7nDbBrz0M_rhNmKvsF9U8FQ@mail.gmail.com>

Jared,

Here is a book that I use in my Game Developer Track at Columbus State CC.
It focuses on programming games which is a good place to start. And it
covers the basics of Python, including object oriented programming. Don't
let the name fool you ... it does go through some complex programming
designs. Good luck.

Dawson, Michael, Python Programming for the absolute beginner, Third Edition

pete



On Sun, Dec 15, 2013 at 4:53 PM, Jared Brock <jaredbrock at sbcglobal.net>wrote:

> Greeting Pythonistas. I am a student with a neglegible amount of
> programming experience who was referred to both Python and this group as a
> way to learn the language. I am looking for suggestings on books, websites,
> or other materials that can serve as a good starting place. The one online
> tutorial I found (http://docs.python.org/2/tutorial/index.html) did have
> examples of basic concepts but lacked any suggested problems to solve to
> reinforce those concepts.
> And in case someone asks, I am not currently able to make it to the Friday
> DoJo's for the time being.
>
> Thanks for reading, and double thanks for replies.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From jaredbrock at sbcglobal.net  Mon Dec 16 18:56:51 2013
From: jaredbrock at sbcglobal.net (Jared Brock)
Date: Mon, 16 Dec 2013 09:56:51 -0800 (PST)
Subject: [CentralOH] Looking for Introductory Python Materials
In-Reply-To: <CAN67YM6thmOXus-dx8pV4L+6U5prJ5V0YLYHfCap08qg1vUZdg@mail.gmail.com>
References: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
 <CAN67YM6thmOXus-dx8pV4L+6U5prJ5V0YLYHfCap08qg1vUZdg@mail.gmail.com>
Message-ID: <1387216611.49517.YahooMailNeo@web180905.mail.ne1.yahoo.com>

Thanks for the help. I've put in a request to the library for the mentioned book, and am going through the various links and see if they have what I'm looking for.Currently looking at the Google class, the learn python site, and MIT OPW materials. I expect to find what I'm looking for in one or more of these options. Thanks again.
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From erik.n.welch at gmail.com  Mon Dec 16 19:42:35 2013
From: erik.n.welch at gmail.com (Erik Welch)
Date: Mon, 16 Dec 2013 13:42:35 -0500
Subject: [CentralOH] Looking for Introductory Python Materials
In-Reply-To: <1387216611.49517.YahooMailNeo@web180905.mail.ne1.yahoo.com>
References: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
 <CAN67YM6thmOXus-dx8pV4L+6U5prJ5V0YLYHfCap08qg1vUZdg@mail.gmail.com>
 <1387216611.49517.YahooMailNeo@web180905.mail.ne1.yahoo.com>
Message-ID: <CAGbNH0oB6NfnVRVWcS42kD33jh738=nz4sPCXY-3o=cwMva76g@mail.gmail.com>

Here is a list of Python resources on the internet that are suitable for
all levels of expertise:

https://github.com/kirang89/pycrumbs/blob/master/pycrumbs.md


On Mon, Dec 16, 2013 at 12:56 PM, Jared Brock <jaredbrock at sbcglobal.net>wrote:

> Thanks for the help. I've put in a request to the library for the
> mentioned book, and am going through the various links and see if they have
> what I'm looking for. Currently looking at the Google class, the learn
> python site, and MIT OPW materials. I expect to find what I'm looking for
> in one or more of these options. Thanks again.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From langfod at gmail.com  Tue Dec 17 02:29:47 2013
From: langfod at gmail.com (David Langford)
Date: Mon, 16 Dec 2013 20:29:47 -0500
Subject: [CentralOH] Looking for Introductory Python Materials
In-Reply-To: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
References: <1387144417.91262.YahooMailNeo@web180906.mail.ne1.yahoo.com>
Message-ID: <CAFwOKtAuMrJW2t+AqwJo07S=W8nOciDQkp6B-daxt6BOroumxw@mail.gmail.com>

I see that the pycrumbs list got mentioned so some of these may be
redundant but here are some of course sites I have found:

https://www.udacity.com/course/cs101

https://www.edx.org/course/mitx/mitx-6-00-1x-introduction-computer-1122 (One
section just finished though the materials are still available - it should
run again for the whole course in a couple months)

https://www.coursera.org/course/programming1

https://www.coursera.org/course/interactivepython

https://www.khanacademy.org/science/computer-science-subject/computer-science

http://www.reddit.com/r/learnpython/

http://www.learnstreet.com/lessons/study/python

https://online.dr-chuck.com/index.php

http://opentechschool.github.io/python-beginners/en/index.html

http://programarcadegames.com/

http://interactivepython.org/courselib/static/thinkcspy/index.html







On Sun, Dec 15, 2013 at 4:53 PM, Jared Brock <jaredbrock at sbcglobal.net>wrote:

> Greeting Pythonistas. I am a student with a neglegible amount of
> programming experience who was referred to both Python and this group as a
> way to learn the language. I am looking for suggestings on books, websites,
> or other materials that can serve as a good starting place. The one online
> tutorial I found (http://docs.python.org/2/tutorial/index.html) did have
> examples of basic concepts but lacked any suggested problems to solve to
> reinforce those concepts.
> And in case someone asks, I am not currently able to make it to the Friday
> DoJo's for the time being.
>
> Thanks for reading, and double thanks for replies.
>
> _______________________________________________
> CentralOH mailing list
> CentralOH at python.org
> https://mail.python.org/mailman/listinfo/centraloh
>
>
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From jep200404 at columbus.rr.com  Sat Dec 21 04:02:12 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Fri, 20 Dec 2013 22:02:12 -0500
Subject: [CentralOH] =?utf-8?q?2013-12-13_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8=?=
Message-ID: <20131220220212.046a86c9.jep200404@columbus.rr.com>

4 folks

http://drupalcampohio.org/drupalcamp-ohio-2013
http://www.meetup.com/Central-Ohio-Drupal/events/146963472/

use pytest instead of unittest
https://pypi.python.org/pypi/pytest
https://wiki.python.org/moin/PyTest

oh my:
    wp:Fallingwater
        get the in-depth tour
    wp:Kentuck Knob
    wp:Polymath Park
        sleep in a Usonian house

wp:Robber_baron_(industrialist)

scallion, green onion, spring onion
coconut milk packets
laksa paste
wp:laksa

From jep200404 at columbus.rr.com  Sat Dec 21 04:15:25 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Fri, 20 Dec 2013 22:15:25 -0500
Subject: [CentralOH] =?utf-8?q?2013-12-20_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8=?=
Message-ID: <20131220221525.6fe4d82f.jep200404@columbus.rr.com>

Knuth & McIlroy
http://www.leancrew.com/all-this/2011/12/more-shell-less-egg/

Why Pascal is Not My Favorite Programming Language
Brian W. Kernighan, April 2, 1981
AT&T Bell Laboratories,  Murray Hill, New Jersey 07974
http://cm.bell-labs.com/cm/cs/cstr/100.ps.gz
http://www.lysator.liu.se/c/bwk-on-pascal.html

"Compatibility means deliberately repeating other people's mistakes."

"wp:" prefix means Wikipedia. 
E.g., "wp:foo" indicates http://en.wikipedia.org/wiki/Foo

Review Brandon Rhodes presentation about structure of code
lightning version of PyCon Ireland 2013 presentation
https://mail.python.org/pipermail/centraloh/2013-October/001867.html

What is the Pace of Pace Wheeler in 
"http://rhodesmill.org/brandon/slides/2013-10-pyconie/"?

isolate I/O code

nifty:
    tr -cs A-Za-z '\n'

wp:David Wheeler (computer scientist)
wp:Burrows?Wheeler transform

wp:trie

From jep200404 at columbus.rr.com  Sun Dec 29 13:52:18 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Sun, 29 Dec 2013 07:52:18 -0500
Subject: [CentralOH] =?utf-8?q?2013-12-27_=E9=81=93=E5=A0=B4_Scribbles_?=
 =?utf-8?b?76SY5pu4L+aDoeaWhz8=?=
Message-ID: <20131229075218.39fd8649.jep200404@columbus.rr.com>

A Raspberry Pi was given away for free.
It was the desirable B model with 512 MB of RAM.

"wp:" prefix means Wikipedia. 
E.g., "wp:foo" indicates http://en.wikipedia.org/wiki/Foo

@@@@@@@@@@@@
    from a browser, upload file to server that is running Django.
    then want Django to process the uploaded 

    https://docs.djangoproject.com/en/dev/topics/files/
    https://docs.djangoproject.com/en/dev/ref/models/fields/#django.db.models.FileField
    http://stackoverflow.com/questions/5871730/need-a-minimal-django-file-upload-example

    wp:Albania
    wp:Albanian_language
    http://www.djangobook.com/en/2.0/index.html

Brandon Rhodes's Astronomy presentation came up again as a good tour of 
what Ipython Notebook can do.
https://mail.python.org/pipermail/centraloh/2013-February/001551.html

wp:Convex function

excellent super nerdy with classic old personal computers
wp:Computer Chess (film)
The Austin Goodwill Computer Museum is credited.
http://goodwillcomputermuseum.org/about.html
Likely they lent parts of their collection for making the movie.
wp:Erhard Seminars Training
wp:Do Androids Dream of Electric Sheep?

wp:Yagi-Uda antenna
102.1 MHz FM 0300 to 1500
wp:WCRX-LP

http://nedbatchelder.com/code/cog/
http://susansenator.com/makingpeace.html

From jep200404 at columbus.rr.com  Mon Dec 30 23:39:43 2013
From: jep200404 at columbus.rr.com (jep200404 at columbus.rr.com)
Date: Mon, 30 Dec 2013 17:39:43 -0500
Subject: [CentralOH] XY Problem
In-Reply-To: <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
References: <20131210165730.1c12b5b8.jep200404@columbus.rr.com>
 <CAJShLf9ZtXF+zFOtk91Lphq8VLktA2wWndoNp89-QecOdF5_HQ@mail.gmail.com>
Message-ID: <20131230173943.121e4207.jep200404@columbus.rr.com>

On Tue, 10 Dec 2013 17:09:26 -0500, Thomas Winningham <winningham at gmail.com> wrote:

> Wanted to mention in relation the first link or so, 
> the Perl people talk about the XY problem:

> http://www.perlmonks.org/index.pl?node_id=542341 

That's a great link.

Now just to confuse things,
let's see what reaction we get from XY about XY being a problem.