From rays at blue-cove.com  Sat Feb  1 17:50:22 2014
From: rays at blue-cove.com (RayS)
Date: Sat, 01 Feb 2014 14:50:22 -0800
Subject: [AstroPy] striding through arbitrarily large files
Message-ID: <201402012250.s11MoPVM003787@blue-cove.com>

I hope this isn't too off-topic for astro, but I know many here work 
with huge files.

I was struggling yesterday with  methods of reading large disk files 
into numpy efficiently (not FITS, just raw files of IEEE floats). 
When loading arbitrarily large files it would be nice to not bother 
reading more than the plot can display before zooming in.

With a 2GB file, I want to read n (like 4096) evenly sampled points out of it.
I tried making a dtype, and other tricks, to read "Pythonically", but 
failed. I broke down and used a for loop with fh.seek() and fromstring()

num_channels = 9
desired_len = 4096
bytes_per_val = numpy.dtype(numpy.float32).itemsize
f_obj = open(path, 'rb')
f_obj.seek(0,2)
file_length = f_obj.tell()
f_obj.seek(0,0)
bytes_per_smp = num_channels * bytes_per_val
num_samples = file_length / bytes_per_smp
stride_smps = num_samples / desired_len ## an int
stride_bytes = stride_smps * bytes_per_smp

arr = numpy.zeros((desired_len, 9))
for i in range(0, desired_len, 1):
     f_obj.seek(i*stride_bytes, 0)
     arr[i] = numpy.fromstring(f_obj.read(36), dtype='f32', count=9)

So, is there a better way to move the pointer through the file 
without a for loop?
Would a generator be much faster?

The dtype and other methods like mmap fail with memoryError, although 
apparently you can mmap with 64bit systems.

- Ray

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From indiajoe at gmail.com  Sun Feb  2 09:10:21 2014
From: indiajoe at gmail.com (Joe Philip Ninan)
Date: Sun, 2 Feb 2014 19:40:21 +0530
Subject: [AstroPy] Inheriting HDUList
Message-ID: <CAJ_T+b64ETY77Gd1UHr7b_y01wSj-TStZPG+=KpQh=dQW=Q5Pg@mail.gmail.com>

Hi,
Is there any online example of how to create a new child object from
HDUList of astropy.io.fits ?  (The object astropy.io.fits.open() returns).
I want to create an object class which inherits everything from HDUList,
and then add some additional functions.
The part i cannot figure out is how to initialize the HDUList inside the
new class.

class MyFitsObject(HDUList):
    def __init__(self,filename):
    # How do i initialise HDUList here, when all i have is the Fits File
name?

-cheers
joe


-- 
/---------------------------------------------------------------
"GNU/Linux: because a PC is a terrible thing to waste" -  GNU Generation

************************************************
Joe Philip Ninan
Research Scholar        /________________\
DAA,                            | Vadakeparambil |
TIFR,                           | Pullad P.O.         |
Mumbai-05, India.      | Kerala, India      |
Ph: +917738438212   | PIN:689548       |
------------------------------\_______________/--------------
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From jzuhone at gmail.com  Sun Feb  2 09:34:58 2014
From: jzuhone at gmail.com (John ZuHone)
Date: Sun, 2 Feb 2014 09:34:58 -0500
Subject: [AstroPy] Inheriting HDUList
In-Reply-To: <CAJ_T+b64ETY77Gd1UHr7b_y01wSj-TStZPG+=KpQh=dQW=Q5Pg@mail.gmail.com>
References: <CAJ_T+b64ETY77Gd1UHr7b_y01wSj-TStZPG+=KpQh=dQW=Q5Pg@mail.gmail.com>
Message-ID: <7EE3B1C0-678D-40F8-9B6A-BD91B65498C4@gmail.com>

Hi Joe,

Have a look at this one:

https://bitbucket.org/yt_analysis/yt/src/6120c77c828f195f8691806fc724bb730fe90680/yt/utilities/fits_image.py?at=yt-3.0

Best,

John Z

On Feb 2, 2014, at 9:10 AM, Joe Philip Ninan <indiajoe at gmail.com> wrote:

> Hi,
> Is there any online example of how to create a new child object from HDUList of astropy.io.fits ?  (The object astropy.io.fits.open() returns).
> I want to create an object class which inherits everything from HDUList, and then add some additional functions.
> The part i cannot figure out is how to initialize the HDUList inside the new class.
> 
> class MyFitsObject(HDUList):
>     def __init__(self,filename):
>     # How do i initialise HDUList here, when all i have is the Fits File name?
> 
> -cheers
> joe
> 
> 
> -- 
> /---------------------------------------------------------------
> "GNU/Linux: because a PC is a terrible thing to waste" -  GNU Generation
> 
> ************************************************
> Joe Philip Ninan       
> Research Scholar        /________________\
> DAA,                            | Vadakeparambil |
> TIFR,                           | Pullad P.O.         |
> Mumbai-05, India.      | Kerala, India      |
> Ph: +917738438212   | PIN:689548       |
> ------------------------------\_______________/--------------
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy



From indiajoe at gmail.com  Mon Feb  3 06:35:12 2014
From: indiajoe at gmail.com (Joe Philip Ninan)
Date: Mon, 3 Feb 2014 17:05:12 +0530
Subject: [AstroPy] Inheriting HDUList
In-Reply-To: <7EE3B1C0-678D-40F8-9B6A-BD91B65498C4@gmail.com>
References: <CAJ_T+b64ETY77Gd1UHr7b_y01wSj-TStZPG+=KpQh=dQW=Q5Pg@mail.gmail.com>
	<7EE3B1C0-678D-40F8-9B6A-BD91B65498C4@gmail.com>
Message-ID: <CAJ_T+b6fAUv7c-cVw2VDfO0ZvSLLFUcc7PAq-PBgD=WYsmLNtw@mail.gmail.com>

Hi John,
Thanks a lot for the link.
On a quick look, it doesn't seem very obvious to me how exactly to
load the data along with initialising the HDUList.
But i shall go through it more carefully to understand.
Thanks again,
-cheers
joe

On 2 February 2014 20:04, John ZuHone <jzuhone at gmail.com> wrote:
> Hi Joe,
>
> Have a look at this one:
>
> https://bitbucket.org/yt_analysis/yt/src/6120c77c828f195f8691806fc724bb730fe90680/yt/utilities/fits_image.py?at=yt-3.0
>
> Best,
>
> John Z
>
> On Feb 2, 2014, at 9:10 AM, Joe Philip Ninan <indiajoe at gmail.com> wrote:
>
>> Hi,
>> Is there any online example of how to create a new child object from HDUList of astropy.io.fits ?  (The object astropy.io.fits.open() returns).
>> I want to create an object class which inherits everything from HDUList, and then add some additional functions.
>> The part i cannot figure out is how to initialize the HDUList inside the new class.
>>
>> class MyFitsObject(HDUList):
>>     def __init__(self,filename):
>>     # How do i initialise HDUList here, when all i have is the Fits File name?
>>
>> -cheers
>> joe
>>
>>
>> --
>> /---------------------------------------------------------------
>> "GNU/Linux: because a PC is a terrible thing to waste" -  GNU Generation
>>
>> ************************************************
>> Joe Philip Ninan
>> Research Scholar        /________________\
>> DAA,                            | Vadakeparambil |
>> TIFR,                           | Pullad P.O.         |
>> Mumbai-05, India.      | Kerala, India      |
>> Ph: +917738438212   | PIN:689548       |
>> ------------------------------\_______________/--------------
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>



-- 
/---------------------------------------------------------------
"GNU/Linux: because a PC is a terrible thing to waste" -  GNU Generation

************************************************
Joe Philip Ninan
Research Scholar        /________________\
DAA,                            | Vadakeparambil |
TIFR,                           | Pullad P.O.         |
Mumbai-05, India.      | Kerala, India      |
Ph: +917738438212   | PIN:689548       |
------------------------------\_______________/--------------


From embray at stsci.edu  Mon Feb  3 14:16:32 2014
From: embray at stsci.edu (Erik Bray)
Date: Mon, 3 Feb 2014 14:16:32 -0500
Subject: [AstroPy] striding through arbitrarily large files
In-Reply-To: <201402012250.s11MoPVM003787@blue-cove.com>
References: <201402012250.s11MoPVM003787@blue-cove.com>
Message-ID: <52EFEB10.1090502@stsci.edu>

Indeed, normally I would suggest just to use mmap, but if you really have to 
support 32-bit systems that won't help you as much as one might like.  As it is 
what you are doing is mostly what you need to do for Numpy, but you don't need 
to do thankfully is read a string from the file and then use numpy.fromstring.

I actually only just discovered this myself, as it is undocumented, and have yet 
to fix it in PyFITS.  But if you pass numpy.fromfile an open file object it will 
read starting from wherever the file pointer is positioned, rather than the 
beginning of the file.

So you can just:

f = open('array.raw', 'rb')
f.seek(np.dtype('float32').itemsize * offset)
section = np.fromfile(f, dtype='float32')

So that at least saves you from having to perform the read() first.

Erik

On 02/01/2014 05:50 PM, RayS wrote:
> I hope this isn't too off-topic for astro, but I know many here work with huge
> files.
>
> I was struggling yesterday with  methods of reading large disk files into numpy
> efficiently (not FITS, just raw files of IEEE floats). When loading arbitrarily
> large files it would be nice to not bother reading more than the plot can
> display before zooming in.
>
> With a 2GB file, I want to read n (like 4096) evenly sampled points out of it.
> I tried making a dtype, and other tricks, to read "Pythonically", but failed. I
> broke down and used a for loop with fh.seek() and fromstring()
>
> num_channels = 9
> desired_len = 4096
> bytes_per_val = numpy.dtype(numpy.float32).itemsize
> f_obj = open(path, 'rb')
> f_obj.seek(0,2)
> file_length = f_obj.tell()
> f_obj.seek(0,0)
> bytes_per_smp = num_channels * bytes_per_val
> num_samples = file_length / bytes_per_smp
> stride_smps = num_samples / desired_len ## an int
> stride_bytes = stride_smps * bytes_per_smp
>
> arr = numpy.zeros((desired_len, 9))
> for i in range(0, desired_len, 1):
>      f_obj.seek(i*stride_bytes, 0)
>      arr[i] = numpy.fromstring(f_obj.read(36), dtype='f32', count=9)
>
> So, is there a better way to move the pointer through the file without a for loop?
> Would a generator be much faster?
>
> The dtype and other methods like mmap fail with memoryError, although apparently
> you can mmap with 64bit systems.
>
> - Ray
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



From embray at stsci.edu  Mon Feb  3 14:30:09 2014
From: embray at stsci.edu (Erik Bray)
Date: Mon, 3 Feb 2014 14:30:09 -0500
Subject: [AstroPy] Inheriting HDUList
In-Reply-To: <CAJ_T+b64ETY77Gd1UHr7b_y01wSj-TStZPG+=KpQh=dQW=Q5Pg@mail.gmail.com>
References: <CAJ_T+b64ETY77Gd1UHr7b_y01wSj-TStZPG+=KpQh=dQW=Q5Pg@mail.gmail.com>
Message-ID: <52EFEE41.6020908@stsci.edu>

On 02/02/2014 09:10 AM, Joe Philip Ninan wrote:
> Hi,
> Is there any online example of how to create a new child object from HDUList of
> astropy.io.fits ?  (The object astropy.io.fits.open() returns).
> I want to create an object class which inherits everything from HDUList, and
> then add some additional functions.
> The part i cannot figure out is how to initialize the HDUList inside the new class.
>
> class MyFitsObject(HDUList):
>      def __init__(self,filename):
>      # How do i initialise HDUList here, when all i have is the Fits File name?

Hi,

It depends on exactly what you want to do--you have to be careful as HDUList has 
a bit of internal state that needs to be managed, but for the most part if you 
just want to extend it with some new methods it's safe enough.  But it's hard to 
help without knowing exactly what you need to do.

One thing I would emphatically *not* recommend is to pass a filename to your 
__init__, but again it depends on exactly what you need the subclass to do. 
Normally HDUList is treated as a more abstract datastructure that may or may not 
have actually come from a file on disk.  HDUList.fromfile should be used to read 
an HDUList from a file (in fact it's basically what pyfits.open() wraps).

The base HDUList.__init__ simply accepts a list of HDU objects to add to the list.

Erik



From embray at stsci.edu  Mon Feb  3 14:32:30 2014
From: embray at stsci.edu (Erik Bray)
Date: Mon, 3 Feb 2014 14:32:30 -0500
Subject: [AstroPy] Inheriting HDUList
In-Reply-To: <52EFEE41.6020908@stsci.edu>
References: <CAJ_T+b64ETY77Gd1UHr7b_y01wSj-TStZPG+=KpQh=dQW=Q5Pg@mail.gmail.com>
	<52EFEE41.6020908@stsci.edu>
Message-ID: <52EFEECE.2000401@stsci.edu>

On 02/03/2014 02:30 PM, Erik Bray wrote:
> On 02/02/2014 09:10 AM, Joe Philip Ninan wrote:
>> Hi,
>> Is there any online example of how to create a new child object from HDUList of
>> astropy.io.fits ?  (The object astropy.io.fits.open() returns).
>> I want to create an object class which inherits everything from HDUList, and
>> then add some additional functions.
>> The part i cannot figure out is how to initialize the HDUList inside the new class.
>>
>> class MyFitsObject(HDUList):
>>       def __init__(self,filename):
>>       # How do i initialise HDUList here, when all i have is the Fits File name?
>
> Hi,
>
> It depends on exactly what you want to do--you have to be careful as HDUList has
> a bit of internal state that needs to be managed, but for the most part if you
> just want to extend it with some new methods it's safe enough.  But it's hard to
> help without knowing exactly what you need to do.
>
> One thing I would emphatically *not* recommend is to pass a filename to your
> __init__, but again it depends on exactly what you need the subclass to do.
> Normally HDUList is treated as a more abstract datastructure that may or may not
> have actually come from a file on disk.  HDUList.fromfile should be used to read
> an HDUList from a file (in fact it's basically what pyfits.open() wraps).
>
> The base HDUList.__init__ simply accepts a list of HDU objects to add to the list.

I should add, the example John sent from the yt project is a good example of how 
to extend the HDUList class.  +1 to it.

Erik



From rays at blue-cove.com  Mon Feb  3 16:27:42 2014
From: rays at blue-cove.com (RayS)
Date: Mon, 03 Feb 2014 13:27:42 -0800
Subject: [AstroPy] striding through arbitrarily large files
In-Reply-To: <52EFEB10.1090502@stsci.edu>
References: <201402012250.s11MoPVM003787@blue-cove.com>
	<52EFEB10.1090502@stsci.edu>
Message-ID: <201402032127.s13LRj1L025946@blue-cove.com>

Nice tip, thank you. I will add the count= option to the fromfile() 
call to get my 9 channels of the sample - otherwise the default is to 
read the rest of the file.

I have to support 32bit Python for now (on 64 bit machines), until 
mayavi supports 64. I haven't found a better, easily usable and fast 
3D surface library.

Ray


At 11:16 AM 2/3/2014, Erik Bray wrote:
>Indeed, normally I would suggest just to use mmap, but if you really have to
>support 32-bit systems that won't help you as much as one might 
>like.  As it is
>what you are doing is mostly what you need to do for Numpy, but you 
>don't need
>to do thankfully is read a string from the file and then use numpy.fromstring.
>
>I actually only just discovered this myself, as it is undocumented, 
>and have yet
>to fix it in PyFITS.  But if you pass numpy.fromfile an open file 
>object it will
>read starting from wherever the file pointer is positioned, rather than the
>beginning of the file.
>
>So you can just:
>
>f = open('array.raw', 'rb')
>f.seek(np.dtype('float32').itemsize * offset)
>section = np.fromfile(f, dtype='float32')
>
>So that at least saves you from having to perform the read() first.
>
>Erik
>
>On 02/01/2014 05:50 PM, RayS wrote:
> > I hope this isn't too off-topic for astro, but I know many here 
> work with huge
> > files.
> >
> > I was struggling yesterday with  methods of reading large disk 
> files into numpy
> > efficiently (not FITS, just raw files of IEEE floats). When 
> loading arbitrarily
> > large files it would be nice to not bother reading more than the plot can
> > display before zooming in.
> >
> > With a 2GB file, I want to read n (like 4096) evenly sampled 
> points out of it.
> > I tried making a dtype, and other tricks, to read "Pythonically", 
> but failed. I
> > broke down and used a for loop with fh.seek() and fromstring()
> >
> > num_channels = 9
> > desired_len = 4096
> > bytes_per_val = numpy.dtype(numpy.float32).itemsize
> > f_obj = open(path, 'rb')
> > f_obj.seek(0,2)
> > file_length = f_obj.tell()
> > f_obj.seek(0,0)
> > bytes_per_smp = num_channels * bytes_per_val
> > num_samples = file_length / bytes_per_smp
> > stride_smps = num_samples / desired_len ## an int
> > stride_bytes = stride_smps * bytes_per_smp
> >
> > arr = numpy.zeros((desired_len, 9))
> > for i in range(0, desired_len, 1):
> >      f_obj.seek(i*stride_bytes, 0)
> >      arr[i] = numpy.fromstring(f_obj.read(36), dtype='f32', count=9)
> >
> > So, is there a better way to move the pointer through the file 
> without a for loop?
> > Would a generator be much faster?
> >
> > The dtype and other methods like mmap fail with memoryError, 
> although apparently
> > you can mmap with 64bit systems.
> >
> > - Ray
> >
> >
> >
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > http://mail.scipy.org/mailman/listinfo/astropy
> >
>
>_______________________________________________
>AstroPy mailing list
>AstroPy at scipy.org
>http://mail.scipy.org/mailman/listinfo/astropy
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From trive at astro.su.se  Fri Feb  7 12:49:25 2014
From: trive at astro.su.se (=?ISO-8859-1?Q?Th=F8ger_Emil_Rivera-Thorsen?=)
Date: Fri, 07 Feb 2014 18:49:25 +0100
Subject: [AstroPy] Coordinates help
Message-ID: <52F51CA5.6010502@astro.su.se>

Hello;

I am doingmy first foraging into the Astropy coordinates and wcs modules.
My job is to check pointings on some blind-offset spectroscopy 
observations from the aqcuisition frames. What I have is this:

1) RA, DEC of reference object.
2) dx, dy offsets in arcsecs along the image axes to the object
3) RA, DEC of the object

What I need to do now is to check that, starting at the center pixel and 
moving along, I actually end up at 3) (and secondarily, that center 
pixel and 1) agree).

2) is really the difficult step here. Can anyone give some hints?




From d.berry at jach.hawaii.edu  Fri Feb  7 13:11:27 2014
From: d.berry at jach.hawaii.edu (David Berry)
Date: Fri, 7 Feb 2014 18:11:27 +0000
Subject: [AstroPy] Coordinates help
In-Reply-To: <52F51CA5.6010502@astro.su.se>
References: <52F51CA5.6010502@astro.su.se>
Message-ID: <CAALafn6BnvO9cbNDsHRP=yqfPNpNny9Uo0TUWS0oUH-kCzZ2Pg@mail.gmail.com>

On 7 February 2014 17:49, Th?ger Emil Rivera-Thorsen <trive at astro.su.se> wrote:
> Hello;
>
> I am doingmy first foraging into the Astropy coordinates and wcs modules.
> My job is to check pointings on some blind-offset spectroscopy
> observations from the aqcuisition frames. What I have is this:
>
> 1) RA, DEC of reference object.
> 2) dx, dy offsets in arcsecs along the image axes to the object
> 3) RA, DEC of the object
>
> What I need to do now is to check that, starting at the center pixel and
> moving along, I actually end up at 3) (and secondarily, that center
> pixel and 1) agree).

I think to do this you will also need to know the orientation of the
image axes with respect to RA and Dec.

David

> 2) is really the difficult step here. Can anyone give some hints?
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From bkloppenborg at gmail.com  Fri Feb  7 23:22:55 2014
From: bkloppenborg at gmail.com (Brian Kloppenborg)
Date: Fri, 07 Feb 2014 23:22:55 -0500
Subject: [AstroPy] SQL-like queries against astropy.table objects
Message-ID: <52F5B11F.60403@gmail.com>

Greetings,

I have unfortunately fallen quite far behind on astropy development and 
my knowledge of the finer features of many of Python's libraries is 
limited because I do most of my work in C/C++.

I have a use case in which I have a small (< 100k row) amount of static 
data which I need to both visualize and be able to easily manipulate 
(grouping, inclusion/exclusion based upon some criteria, application of 
some simple mathematics without altering the original data). I've used 
SQL extensively in the past and the queries which I would run are a 
perfect use case; however, visualizing the data with matplotlib (or 
similar) might be more efficiently accomplished from an astropy.table 
object. Is it possible to run an SQL-like query against an astropy.table 
object? If not with SQL-like syntax, how else could this be done?

For example, say I have a table with the following columns (not the use 
case, but an easy demo):
JD, mag, mag_error

I could find all data points with an SNR > 100 within a date range by:
     SELECT * from table WHERE (JD > value AND JD < value AND 
mag/mag_err > 100);
quite quickly. Conversely, implementing something similar using numpy 
operations appears to be quite painful (e.g. 
http://stackoverflow.com/questions/7169240/moving-large-sql-query-to-numpy) 
unless this is already built-in to astropy.table objects.

Kind regards,
Brian Kloppenborg


From ejensen1 at swarthmore.edu  Sat Feb  8 09:00:32 2014
From: ejensen1 at swarthmore.edu (Eric Jensen)
Date: Sat, 8 Feb 2014 09:00:32 -0500
Subject: [AstroPy] SQL-like queries against astropy.table objects
In-Reply-To: <52F5B11F.60403@gmail.com>
References: <52F5B11F.60403@gmail.com>
Message-ID: <CBD233FB-4FAB-434C-8FE2-2EA05506AA7F@swarthmore.edu>

Hi Brian,

I think that your use case is actually pretty straightforward in an astropy table, since you just want to pull out a subset of the table.  It seems that what's tricky in the stackoverflow example you linked to is the JOIN and GROUPBY parts of the query, not the selection.

You can easily select rows that meet multiple criteria, and use the resulting boolean array to create a new table with the subset of data you want.  Here's an example, not with your variables but just using a text file of interferometry complex visibilities I had around (U, V, W baseline lengths, real and imaginary parts of the visibility): 

In [32]:

from astropy.table import Table, Column
import numpy as np
In [33]:

t = Table.read('test_data.txt', format='ascii.commented_header')
In [34]:

t.colnames
Out[34]:
['U', 'V', 'W', 'Real', 'Imag', 'Weight', 'Freq']
In [35]:

# Select only entries with long baselines in U and W, and Real amplitudes > 1 Jy:
good_rows = np.logical_and(t['U'] > 100, t['V'] > 100, t['Real'] > 1)
In [42]:

# Make a new table from this selection, and see how many rows were in 
# new table vs. the original one:
new_table = t[good_rows]
new_table['U'].shape

Out[42]:
(120,)
In [41]:

t['U'].shape
Out[41]:
(4500,)

There might be even better ways to do it (and there is almost certainly a cleaner way to get the number of rows in a table than calling 'shape' on one column), but this should give you the basic idea of the sort of selection that it seem like you're looking for. 

There's also a table-joining function:

http://docs.astropy.org/en/latest/api/astropy.table.operations.join.html#astropy.table.operations.join

For more complex operations, others who are more familiar with both astropy and SQL can chime in, but thought I'd offer what (little) I know on the selection part. 

Hope this helps,

Eric



On Feb 7, 2014, at 11:22 PM, Brian Kloppenborg wrote:

> Greetings,
> 
> I have unfortunately fallen quite far behind on astropy development and 
> my knowledge of the finer features of many of Python's libraries is 
> limited because I do most of my work in C/C++.
> 
> I have a use case in which I have a small (< 100k row) amount of static 
> data which I need to both visualize and be able to easily manipulate 
> (grouping, inclusion/exclusion based upon some criteria, application of 
> some simple mathematics without altering the original data). I've used 
> SQL extensively in the past and the queries which I would run are a 
> perfect use case; however, visualizing the data with matplotlib (or 
> similar) might be more efficiently accomplished from an astropy.table 
> object. Is it possible to run an SQL-like query against an astropy.table 
> object? If not with SQL-like syntax, how else could this be done?
> 
> For example, say I have a table with the following columns (not the use 
> case, but an easy demo):
> JD, mag, mag_error
> 
> I could find all data points with an SNR > 100 within a date range by:
>     SELECT * from table WHERE (JD > value AND JD < value AND 
> mag/mag_err > 100);
> quite quickly. Conversely, implementing something similar using numpy 
> operations appears to be quite painful (e.g. 
> http://stackoverflow.com/questions/7169240/moving-large-sql-query-to-numpy) 
> unless this is already built-in to astropy.table objects.
> 
> Kind regards,
> Brian Kloppenborg
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy

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From derek at astro.physik.uni-goettingen.de  Sat Feb  8 12:28:27 2014
From: derek at astro.physik.uni-goettingen.de (Derek Homeier)
Date: Sat, 8 Feb 2014 18:28:27 +0100
Subject: [AstroPy] SQL-like queries against astropy.table objects
In-Reply-To: <CBD233FB-4FAB-434C-8FE2-2EA05506AA7F@swarthmore.edu>
References: <52F5B11F.60403@gmail.com>
	<CBD233FB-4FAB-434C-8FE2-2EA05506AA7F@swarthmore.edu>
Message-ID: <070AC50D-2B39-44B2-859B-D7EDA99D52E6@astro.physik.uni-goettingen.de>

Hi,

I know almost nothing about SQL, but I agree that for basic conditionals that can be used
on numpy arrays this really is straightforward.

On 08.02.2014, at 3:00PM, Eric Jensen <ejensen1 at swarthmore.edu> wrote:

> In [35]:
> 
> # Select only entries with long baselines in U and W, and Real amplitudes > 1 Jy:
> good_rows = np.logical_and(t['U'] > 100, t['V'] > 100, t['Real'] > 1)
> In [42]:
> 
> # Make a new table from this selection, and see how many rows were in 
> # new table vs. the original one:
> new_table = t[good_rows]
> new_table['U'].shape
> 
This can be written even more concise, e.g. in the OP's example 

> For example, say I have a table with the following columns (not the use 
> case, but an easy demo):
> JD, mag, mag_error
> 
> I could find all data points with an SNR > 100 within a date range by:
>     SELECT * from table WHERE (JD > value AND JD < value AND 
> mag/mag_err > 100);

new_table = t[[('JD']>minval)&(t['JD']<maxval)&(t['mag']/t['mag_err']>100)]
print(len(t), len(new_table))

directly gives you the desired selection (which works the same with any numpy structured array.
Not very painful, even if it might get a bit lengthy to type. I don't think though apt.Table offers a more
comfortable way like e.g. pytables does with tbl.where('JD>minval & JD<maxval')?

I am sure there's more powerful possibilities in SQL that are not as easy to reproduce;
operating on string columns is a bit more inconvenient, since numpy does not offer a lot of operations
working on arrays of str type; in this case I think  you have to resort to python loops, but in this case
astropy Tables add_column[s] helps a lot over plain numpy. I have not explored the grouping methods
either.

HTH,
 						Derek




From embray at stsci.edu  Mon Feb 10 11:09:23 2014
From: embray at stsci.edu (Erik Bray)
Date: Mon, 10 Feb 2014 11:09:23 -0500
Subject: [AstroPy] SQL-like queries against astropy.table objects
In-Reply-To: <070AC50D-2B39-44B2-859B-D7EDA99D52E6@astro.physik.uni-goettingen.de>
References: <52F5B11F.60403@gmail.com>	<CBD233FB-4FAB-434C-8FE2-2EA05506AA7F@swarthmore.edu>
	<070AC50D-2B39-44B2-859B-D7EDA99D52E6@astro.physik.uni-goettingen.de>
Message-ID: <52F8F9B3.2050504@stsci.edu>

On 02/08/2014 12:28 PM, Derek Homeier wrote:
> Hi,
>
> I know almost nothing about SQL, but I agree that for basic conditionals that can be used
> on numpy arrays this really is straightforward.
>
> On 08.02.2014, at 3:00PM, Eric Jensen <ejensen1 at swarthmore.edu> wrote:
>
>> In [35]:
>>
>> # Select only entries with long baselines in U and W, and Real amplitudes > 1 Jy:
>> good_rows = np.logical_and(t['U'] > 100, t['V'] > 100, t['Real'] > 1)
>> In [42]:
>>
>> # Make a new table from this selection, and see how many rows were in
>> # new table vs. the original one:
>> new_table = t[good_rows]
>> new_table['U'].shape
>>
...

In fairness, for a very *large* table this sort of thing could use up a lot of 
memory, especially considering that Numpy doesn't use bit arrays for boolean 
masks :/

Of course the OP said it was a small table so that's beside the point here; but 
an actual database should provide an efficient row-based iterator with such a 
selection criteria, even hypothetically over millions of rows.  Of course if 
that's what one needs one should just loader their data into a database :)

Erik B.

>
>> For example, say I have a table with the following columns (not the use
>> case, but an easy demo):
>> JD, mag, mag_error
>>
>> I could find all data points with an SNR > 100 within a date range by:
>>      SELECT * from table WHERE (JD > value AND JD < value AND
>> mag/mag_err > 100);
>
> new_table = t[[('JD']>minval)&(t['JD']<maxval)&(t['mag']/t['mag_err']>100)]
> print(len(t), len(new_table))
>
> directly gives you the desired selection (which works the same with any numpy structured array.
> Not very painful, even if it might get a bit lengthy to type. I don't think though apt.Table offers a more
> comfortable way like e.g. pytables does with tbl.where('JD>minval & JD<maxval')?
>
> I am sure there's more powerful possibilities in SQL that are not as easy to reproduce;
> operating on string columns is a bit more inconvenient, since numpy does not offer a lot of operations
> working on arrays of str type; in this case I think  you have to resort to python loops, but in this case
> astropy Tables add_column[s] helps a lot over plain numpy. I have not explored the grouping methods
> either.
>
> HTH,
>   						Derek
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



From aldcroft at head.cfa.harvard.edu  Mon Feb 10 12:52:11 2014
From: aldcroft at head.cfa.harvard.edu (Aldcroft, Thomas)
Date: Mon, 10 Feb 2014 12:52:11 -0500
Subject: [AstroPy] SQL-like queries against astropy.table objects
In-Reply-To: <CBD233FB-4FAB-434C-8FE2-2EA05506AA7F@swarthmore.edu>
References: <52F5B11F.60403@gmail.com>
	<CBD233FB-4FAB-434C-8FE2-2EA05506AA7F@swarthmore.edu>
Message-ID: <CAMtEP6ypVG5HNOacVZ=xPFiuR6uRMJ4EKgMsuPCQjaGbvOgC6A@mail.gmail.com>

On Sat, Feb 8, 2014 at 9:00 AM, Eric Jensen <ejensen1 at swarthmore.edu> wrote:

> Hi Brian,
>
> I think that your use case is actually pretty straightforward in an
> astropy table, since you just want to pull out a subset of the table.  It
> seems that what's tricky in the stackoverflow example you linked to is the
> JOIN and GROUPBY parts of the query, not the selection.
>
> You can easily select rows that meet multiple criteria, and use the
> resulting boolean array to create a new table with the subset of data you
> want.  Here's an example, not with your variables but just using a text
> file of interferometry complex visibilities I had around (U, V, W baseline
> lengths, real and imaginary parts of the visibility):
>
> In [32]:
>
> from astropy.table import Table, Column
>
> import numpy as np
>
> In [33]:
>
> t = Table.read('test_data.txt', format='ascii.commented_header')
>
> In [34]:
>
> t.colnames
>
> Out[34]:
>
> ['U', 'V', 'W', 'Real', 'Imag', 'Weight', 'Freq']
>
> In [35]:
>
> # Select only entries with long baselines in U and W, and Real amplitudes > 1 Jy:
>
> good_rows = np.logical_and(t['U'] > 100, t['V'] > 100, t['Real'] > 1)
>
> In [42]:
>
> # Make a new table from this selection, and see how many rows were in
>
> # new table vs. the original one:
>
> new_table = t[good_rows]
>
> new_table['U'].shape
>
>
> Out[42]:
>
> (120,)
>
> In [41]:
>
> t['U'].shape
>
> Out[41]:
>
> (4500,)
>
>
> There might be even better ways to do it (and there is almost certainly a
> cleaner way to get the number of rows in a table than calling 'shape' on
> one column), but this should give you the basic idea of the sort of
> selection that it seem like you're looking for.
>
> There's also a table-joining function:
>
>
> http://docs.astropy.org/en/latest/api/astropy.table.operations.join.html#astropy.table.operations.join
>
> For more complex operations, others who are more familiar with both
> astropy and SQL can chime in, but thought I'd offer what (little) I know on
> the selection part.
>

In addition to joins, astropy table has some support for group_by and table
concatenation (by rows or columns):

  http://astropy.readthedocs.org/en/latest/table/operations.html

For tables that can be manipulated entirely in memory this should be
reasonably efficient.  Simple selections with boolean arrays as shown
earlier are quite fast and efficient.

Cheers,
Tom



>
> Hope this helps,
>
> Eric
>
>
>
> On Feb 7, 2014, at 11:22 PM, Brian Kloppenborg wrote:
>
> Greetings,
>
> I have unfortunately fallen quite far behind on astropy development and
> my knowledge of the finer features of many of Python's libraries is
> limited because I do most of my work in C/C++.
>
> I have a use case in which I have a small (< 100k row) amount of static
> data which I need to both visualize and be able to easily manipulate
> (grouping, inclusion/exclusion based upon some criteria, application of
> some simple mathematics without altering the original data). I've used
> SQL extensively in the past and the queries which I would run are a
> perfect use case; however, visualizing the data with matplotlib (or
> similar) might be more efficiently accomplished from an astropy.table
> object. Is it possible to run an SQL-like query against an astropy.table
> object? If not with SQL-like syntax, how else could this be done?
>
> For example, say I have a table with the following columns (not the use
> case, but an easy demo):
> JD, mag, mag_error
>
> I could find all data points with an SNR > 100 within a date range by:
>     SELECT * from table WHERE (JD > value AND JD < value AND
> mag/mag_err > 100);
> quite quickly. Conversely, implementing something similar using numpy
> operations appears to be quite painful (e.g.
> http://stackoverflow.com/questions/7169240/moving-large-sql-query-to-numpy)
>
> unless this is already built-in to astropy.table objects.
>
> Kind regards,
> Brian Kloppenborg
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>
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From gb.gabrielebrambilla at gmail.com  Mon Feb 10 13:25:46 2014
From: gb.gabrielebrambilla at gmail.com (Gabriele Brambilla)
Date: Mon, 10 Feb 2014 13:25:46 -0500
Subject: [AstroPy] Fwd: basemap wrapimage
In-Reply-To: <CABmgkieYuR_XP-Kf=jP5M5hTq+Hx1O0LctSu_f7dJLMJKVZnyg@mail.gmail.com>
References: <CABmgkieYuR_XP-Kf=jP5M5hTq+Hx1O0LctSu_f7dJLMJKVZnyg@mail.gmail.com>
Message-ID: <CABmgkifCUZNhyQ0iu=8rqhxRz-m5ZfQi9pC-=ONYGYa-bZjksg@mail.gmail.com>

I am trying to don't save the figures of the plot but to plot them
automatically on a basemap.

this the code I'm trying to run:

fiq = plt.figure()
axf = fiq.add_subplot(111)
imh = axf.imshow(B)
fiq.canvas.draw()

#trying to build a map

degree = list(range(360))
for d in degree:

        map = Basemap(projection='ortho', lat_0 = 0, lon_0 = d, resolution
= 'l', area_thresh = 1000.)
        map.warpimage(image=imh)
        map.drawmapboundary()
        title = str(d)+'.png'
        map.savefig(title)

but it doesn't work. it returns

Traceback (most recent call last):
  File "building3d.py", line 103, in <module>
    map.warpimage(image=imh)
  File "C:\Anaconda\lib\site-packages\mpl_toolkits\basemap\__init__.py",
line 40
06, in warpimage
    if file.startswith('http'):
AttributeError: 'AxesImage' object has no attribute 'startswith'

And I don't find many tutorials on the web...

thanks

Gabriele
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From harrold at astro.as.utexas.edu  Tue Feb 11 19:46:29 2014
From: harrold at astro.as.utexas.edu (Samuel Harrold)
Date: Tue, 11 Feb 2014 18:46:29 -0600
Subject: [AstroPy] astropy stability for time-series differential photometry
	pipeline
Message-ID: <CAAhYzvC8RJ8ZDArL5Nm0DeKoAKPU64cD2rBk+p=reOxWo+PfWw@mail.gmail.com>

Hello,

My research group at UT Austin is considering migrating our data reduction
pipeline from IRAF/PyRAF to astropy. We do time-series differential
photometry for asteroseismology, and because we use our data for many years
after we've processed it, we'd like our pipeline to be stable for 5-10
years. We're unsure if we should wait several years for the astropy
collaboration to release a paper demonstrating comparisons with
IRAF/PyRAF/ESO-MIDAS/other, or if we should migrate now.

We have a few questions about the stability of astropy before we attempt to
migrate. We greatly appreciate any advice:

- In the long term, is STSCI replacing IRAF/PyRAF with astropy?

- If we migrate to astropy now, how often would we need to incorporate
updates to astropy, use non-astropy packages, and/or make our own
work-arounds? Our key pipeline needs are:
- - Operations are done on ~1000 - 5000 images at a time. (We take
sequences of ~10-second exposures for many hours at a time, following the
target from horizon to horizon.)
- - Bias, dark, flat calibration
- - Align calibrated images (to correct for bad tracking)
- - Circular aperture photometry of target star and comparison stars
- - Correct timestamps to BJD with accuracy to better than 0.01s. (Our
instrument's timestamps are controlled by GPS. Light curves are combined
with others taken over ~20 years.)

Thanks for all your help, and thanks for making such a useful tool!
Sam Harrold
----------
Samuel Harrold
PhD Candidate
Astronomy Department
University of Texas at Austin
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From jim.vickroy at noaa.gov  Wed Feb 12 11:06:41 2014
From: jim.vickroy at noaa.gov (jim vickroy)
Date: Wed, 12 Feb 2014 09:06:41 -0700
Subject: [AstroPy] Solar Limb Darkening Removal?
Message-ID: <52FB9C11.1050805@noaa.gov>

Hi,

Is there any existing Python software for the removal of Solar Limb 
darkening?  My on-line search has failed to find anything so far.

Thanks,
-- jv
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From stuart at mumford.me.uk  Wed Feb 12 12:17:38 2014
From: stuart at mumford.me.uk (Stuart Mumford)
Date: Wed, 12 Feb 2014 17:17:38 +0000
Subject: [AstroPy] Solar Limb Darkening Removal?
In-Reply-To: <52FB9C11.1050805@noaa.gov>
References: <52FB9C11.1050805@noaa.gov>
Message-ID: <CAJ3G1JpV1aUQ11wRQ21zFvC=3RAcS=+X=oqF44axjcMN4008TA@mail.gmail.com>

Hi,

You might be interested in SunPy (http://sunpy.org).

We don't have limb darkening code at the moment but we would be willing to
help you out if you wanted to add it.

Stuart


On 12 February 2014 16:06, jim vickroy <jim.vickroy at noaa.gov> wrote:

>  Hi,
>
> Is there any existing Python software for the removal of Solar Limb
> darkening?  My on-line search has failed to find anything so far.
>
> Thanks,
> -- jv
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>
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From jim.vickroy at noaa.gov  Wed Feb 12 13:06:53 2014
From: jim.vickroy at noaa.gov (jim vickroy)
Date: Wed, 12 Feb 2014 11:06:53 -0700
Subject: [AstroPy] {SunPy} Re:  Solar Limb Darkening Removal?
In-Reply-To: <184FE51A-4AB6-48B0-A1BC-747C29826341@gmail.com>
References: <52FB9C11.1050805@noaa.gov>
	<CAJ3G1JpV1aUQ11wRQ21zFvC=3RAcS=+X=oqF44axjcMN4008TA@mail.gmail.com>
	<184FE51A-4AB6-48B0-A1BC-747C29826341@gmail.com>
Message-ID: <52FBB83D.6050900@noaa.gov>

On 2/12/2014 10:38 AM, Steven Christe wrote:
> Hi Jim, I am actually working on this problem currently and have implemented a solution in SunPy. It is currently in a branch on my fork called hmi_fix which you can find here
>
> https://github.com/ehsteve/sunpy/blob/hmi_fix/sunpy/map/sources/sdo.py
>
> under the function called _angle_of_incidence
>
> This function clearly belongs in a higher level than the hmi map class. Let?s discuss what your needs are, what data you are working on, and we can work how we can best help you.
Hello Steven,

Thanks for your interest.  That is good news!

I'm working on automated Solar features classification which uses 
mono-chromatic Solar images at various wavelengths.  Presently, the 
classifier analyzes SDO-AIA (FITS) images, but we want to include 
H-alpha (FITS) images (gong2.nso.edu) to hopefully improve Sunspot and 
filament detection.  However, the limb-darkening, of the H-alpha images, 
is proving problematic.  When GOES-R launches, we will switch to SUVI as 
the UV images source.

Hopefully, I've answered your questions.

What is the next step here?  Shall I download your code and start to play?

-- jv


On Feb 12, 2014, at 12:17 PM, Stuart Mumford <stuart at mumford.me.uk> wrote:
>> Hi,
>>
>> You might be interested in SunPy (http://sunpy.org).
>>
>> We don't have limb darkening code at the moment but we would be willing to help you out if you wanted to add it.
>>
>> Stuart
>>
>>
>> On 12 February 2014 16:06, jim vickroy <jim.vickroy at noaa.gov> wrote:
>> Hi,
>>
>> Is there any existing Python software for the removal of Solar Limb darkening?  My on-line search has failed to find anything so far.
>>
>> Thanks,
>> -- jv
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>>
>>
>> -- 
>> You received this message because you are subscribed to the Google Groups "SunPy" group.
>> To unsubscribe from this group and stop receiving emails from it, send an email to sunpy+unsubscribe at googlegroups.com.
>> To post to this group, send email to sunpy at googlegroups.com.
>> Visit this group at http://groups.google.com/group/sunpy.
>> For more options, visit https://groups.google.com/groups/opt_out.

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From jim.vickroy at noaa.gov  Wed Feb 12 13:15:50 2014
From: jim.vickroy at noaa.gov (jim vickroy)
Date: Wed, 12 Feb 2014 11:15:50 -0700
Subject: [AstroPy] Solar Limb Darkening Removal?
In-Reply-To: <CAJ3G1JpV1aUQ11wRQ21zFvC=3RAcS=+X=oqF44axjcMN4008TA@mail.gmail.com>
References: <52FB9C11.1050805@noaa.gov>
	<CAJ3G1JpV1aUQ11wRQ21zFvC=3RAcS=+X=oqF44axjcMN4008TA@mail.gmail.com>
Message-ID: <52FBBA56.7000404@noaa.gov>

On 2/12/2014 10:17 AM, Stuart Mumford wrote:
> Hi,
>
> You might be interested in SunPy (http://sunpy.org).
>
> We don't have limb darkening code at the moment but we would be 
> willing to help you out if you wanted to add it.
>
> Stuart

Hello Stuart,

Thanks for your response.

I visited http://sunpy.org/help/#list but could not see how to join 
either of  the two lists mentioned. Apologies for being dense on this one.

-- jv


>
>
> On 12 February 2014 16:06, jim vickroy <jim.vickroy at noaa.gov 
> <mailto:jim.vickroy at noaa.gov>> wrote:
>
>     Hi,
>
>     Is there any existing Python software for the removal of Solar
>     Limb darkening?  My on-line search has failed to find anything so far.
>
>     Thanks,
>     -- jv
>
>     _______________________________________________
>     AstroPy mailing list
>     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     http://mail.scipy.org/mailman/listinfo/astropy
>
>

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From stuart at mumford.me.uk  Wed Feb 12 13:21:04 2014
From: stuart at mumford.me.uk (Stuart Mumford)
Date: Wed, 12 Feb 2014 18:21:04 +0000
Subject: [AstroPy] Solar Limb Darkening Removal?
In-Reply-To: <52FBBA56.7000404@noaa.gov>
References: <52FB9C11.1050805@noaa.gov>
	<CAJ3G1JpV1aUQ11wRQ21zFvC=3RAcS=+X=oqF44axjcMN4008TA@mail.gmail.com>
	<52FBBA56.7000404@noaa.gov>
Message-ID: <CAJ3G1JogePJwGM3U2RZSLPDMcRb_fz9yF86pf0PLKxjLeurh8g@mail.gmail.com>

Ooops! should be links there:

https://groups.google.com/forum/#!forum/sunpy
https://groups.google.com/forum/#!forum/sunpy-dev


On 12 February 2014 18:15, jim vickroy <jim.vickroy at noaa.gov> wrote:

>  On 2/12/2014 10:17 AM, Stuart Mumford wrote:
>
>  Hi,
>
>  You might be interested in SunPy (http://sunpy.org).
>
>  We don't have limb darkening code at the moment but we would be willing
> to help you out if you wanted to add it.
>
> Stuart
>
>
> Hello Stuart,
>
> Thanks for your response.
>
> I visited http://sunpy.org/help/#list but could not see how to join
> either of  the two lists mentioned.  Apologies for being dense on this one.
>
> -- jv
>
>
>
>
>
> On 12 February 2014 16:06, jim vickroy <jim.vickroy at noaa.gov> wrote:
>
>>  Hi,
>>
>> Is there any existing Python software for the removal of Solar Limb
>> darkening?  My on-line search has failed to find anything so far.
>>
>> Thanks,
>> -- jv
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>>
>
>
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From shashankshalgar at unm.edu  Wed Feb 12 16:03:43 2014
From: shashankshalgar at unm.edu (Shashank Shalgar)
Date: Wed, 12 Feb 2014 14:03:43 -0700
Subject: [AstroPy] Query regarding astropy.cosmology
Message-ID: <CAJ8JdfXB=+itYA5zJWnzUOfV2xhmfOyC4-jAZ07jBiQaGn5+yw@mail.gmail.com>

Hello,
I just found out about astropy module and it looking really useful. I am
especially interested in the cosmology module. However, I did not find much
documentation on the analysis of CMB anisotropies. I am not sure whether
the analysis of CMB anisotropies is even possible with astropy.cosmology. I
would like to know whether it is possible to get the anisotropy data as
tables in the module as a numpy array so that I can wrote functions to
extract information from it. For eg. correlation length, three point
correlations etc.

Thanks in advance.

Shashank
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From Alexander.Conley at Colorado.EDU  Wed Feb 12 16:15:08 2014
From: Alexander.Conley at Colorado.EDU (Alexander Joseph Conley)
Date: Wed, 12 Feb 2014 14:15:08 -0700
Subject: [AstroPy] Query regarding astropy.cosmology
In-Reply-To: <CAJ8JdfXB=+itYA5zJWnzUOfV2xhmfOyC4-jAZ07jBiQaGn5+yw@mail.gmail.com>
References: <CAJ8JdfXB=+itYA5zJWnzUOfV2xhmfOyC4-jAZ07jBiQaGn5+yw@mail.gmail.com>
Message-ID: <88329F01-E6E6-476A-A84E-544A4AD2073F@colorado.edu>

Hi Shashank,

  No, astropy.cosmology is not intended to do real analysis of the
CMB anisotropies.  That would probably be considered too specialized
for astropy (although it could make an interesting affiliated package
if somebody wanted to develop such a module: http://www.astropy.org/affiliated/)

Alex

On 12-Feb-2014, at 2:03 PM, Shashank Shalgar <shashankshalgar at unm.edu<mailto:shashankshalgar at unm.edu>> wrote:

Hello,
I just found out about astropy module and it looking really useful. I am especially interested in the cosmology module. However, I did not find much documentation on the analysis of CMB anisotropies. I am not sure whether the analysis of CMB anisotropies is even possible with astropy.cosmology. I would like to know whether it is possible to get the anisotropy data as tables in the module as a numpy array so that I can wrote functions to extract information from it. For eg. correlation length, three point correlations etc.

Thanks in advance.

Shashank
_______________________________________________
AstroPy mailing list
AstroPy at scipy.org<mailto:AstroPy at scipy.org>
http://mail.scipy.org/mailman/listinfo/astropy

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From cf5g09 at soton.ac.uk  Fri Feb 14 10:09:55 2014
From: cf5g09 at soton.ac.uk (frohmaier c. (cf5g09))
Date: Fri, 14 Feb 2014 15:09:55 +0000
Subject: [AstroPy] all_pix2world() NULL error
Message-ID: <AC523039-F1EF-4FC4-96FB-EC21753AC3F0@soton.ac.uk>

Hi,

When attempting to run all_pix2world() I get the following error:

ERROR: RuntimeError: NULL error object in wcslib

I cannot find any reference to this in the Astropy documentation. Does anyone know how I can resolve this?

Cheers,
Chris





From stuart at mumford.me.uk  Fri Feb 14 12:36:11 2014
From: stuart at mumford.me.uk (Stuart Mumford)
Date: Fri, 14 Feb 2014 17:36:11 +0000
Subject: [AstroPy] SunPy 0.4.0 Released
Message-ID: <CAJ3G1Jq9sDkHfs_W1y=hwm+cGkjD4z16K=0M5Y8tySxEcxr6_Q@mail.gmail.com>

Hello everyone,

The SunPy community is pleased to announce the release of SunPy 0.4.0.
This release contains many new features, some of which are contributed by
people
who participated in GSOC 2013. It includes the addition of a new local
database for storing
and searching data, it features a HEK to VSO translator and a new HELIO
module in net.
As well as this major work has been undertaken on the documentation and a
new website developed.

To download the lastest SunPy release go to our website http://sunpy.org or
download from PyPI: https://pypi.python.org/pypi/sunpy.
The documentation for the latest release can now be found at
http://docs.sunpy.org/en/stable/http://docs.sunpy.org/en/stable/


This release contains 1025 commits from 19 people.

New Features:


   -  *Major *documentation refactor. A far reaching re-write and
   restructure.
   -  Add a SunPy Database to store and search local data.
   -  Add beta support for querying the HELIO HEC
   -  Add beta HEK to VSO query translation.
   -  Add the ability to download the GOES event list.
   -  Add support for downloading and querying the LYTAF database.
   -  Add support for ANA data.
   -  Updated sun.constants to use astropy.constants objects which include
   units, source, and error instide. For more info check out
   http://docs.astropy.org/en/latest/constants/index.html
   - Add some beta support for IRIS data products
   - Add a new MapCubeAnimator class with interactive widgets which is
   returned by mapcube.peek().
   - The Glymur library is now used to read JPEG2000 files.
   - GOESLightCurve now supports all GOES satellites.




The people who have contributed to this release are:

    Stuart Mumford
    Simon Liedtke
    Steven Christe
    Jack Ireland
    Andrew Inglis
    Nabil Freij
    Samuel Bennett
    David Perez-Suarez
    Pritish Chakraborty
    Albert Y. Shih
    John Evans
    Michael Malocha
    Florian Mayer
    Russell Hewett
    Jose Iv?n Campos
    Keith Hughitt
    Tiago Pereira
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From erik.tollerud at gmail.com  Fri Feb 14 13:00:14 2014
From: erik.tollerud at gmail.com (Erik Tollerud)
Date: Fri, 14 Feb 2014 13:00:14 -0500
Subject: [AstroPy] astropy stability for time-series differential
 photometry pipeline
In-Reply-To: <CAAhYzvC8RJ8ZDArL5Nm0DeKoAKPU64cD2rBk+p=reOxWo+PfWw@mail.gmail.com>
References: <CAAhYzvC8RJ8ZDArL5Nm0DeKoAKPU64cD2rBk+p=reOxWo+PfWw@mail.gmail.com>
Message-ID: <CAARXUwXABdMDWyYwEZ=cBWmQ5hSESmeCHA3vG2bJO_urquM4rg@mail.gmail.com>

Hello Sam,

I'll try to answer your questions below:

> - In the long term, is STSCI replacing IRAF/PyRAF with astropy?

I certainly can't speak for STScI, but I've gotten the impression that
is the intent (or at least a combination of astropy and more specific
in-house python packages they develop).  Perry certainly can make a
more definitive statement about this, though.



> - If we migrate to astropy now, how often would we need to incorporate updates to astropy, use non-astropy packages, and/or make our own work-arounds?

As I've explained below, some of what you're looking for is in Astropy
"affiliated packages".  These are packages that are not part of the
actual Astropy code base, but use the Astropy frameworks or are
otherwise affiliated with the community.  Some of it may eventually
end up in the astropy core package, but we're intentionally leaving it
out for now because there's a lot of development left to be done, and
we want to give this stuff the opportunity to develop de-coupled from
the core.  They generally don't have fixed release cycles, so I can't
say for sure how often you'd need updates.   I think for the purposes
you've described, though, the API's are/will be fairly stable, so you
probably would only need to update if there's a bug fix that is
important for your specific work.

For the Astropy core itself, we have a release cycle every 6 months,
which may introduce backwards-incompatible changes (which would
require updates for you), but we are also planning "LTS" releases
every 2 years.  These will be supported with bugfixes for at least 2
years while remaining backwards-compatible.  We're also planning to do
"soft support" for even longer - e.g., if you're using an LTS that's 3
years old, and find that a crucial bug affects your work, we'd be
filling to just fix that and do a bugfix release. Similarly to the
affiliated packages, though, the needs you've listed in the core
probably won't change substantially once it's in, so you are probably
safe just upgrading to the latest version if you want a new feature.



> - - Operations are done on ~1000 - 5000 images at a time. (We take sequences of ~10-second exposures for many hours at a time, following the target from horizon to horizon.)
> - - Bias, dark, flat calibration
> - - Align calibrated images (to correct for bad tracking)
> - - Circular aperture photometry of target star and comparison stars

All of this is not in the Astropy core package.  Some of it  is in an
astropy affiliated package called `photutils`, though
(https://github.com/astropy/photutils), and the rest is in a
affiliated package that I believe is soon-to-be-released (something
like `ccdproc`).


> - - Correct timestamps to BJD with accuracy to better than 0.01s. (Our instrument's timestamps are controlled by GPS. Light curves are combined with others taken over ~20 years.)

The `astropy.time.Time` object (for representing timestamps) I believe
is at msec accuracy now, but I can't remember know if there's a BJD
correction in there or not.  Marten or Tom A probably know, though
(cced here).



Hopefully that helps!



> Thanks for all your help, and thanks for making such a useful tool!
> Sam Harrold
> ----------
> Samuel Harrold
> PhD Candidate
> Astronomy Department
> University of Texas at Austin
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



-- 
Erik


From mdroe at stsci.edu  Fri Feb 14 15:15:30 2014
From: mdroe at stsci.edu (Michael Droettboom)
Date: Fri, 14 Feb 2014 15:15:30 -0500
Subject: [AstroPy] all_pix2world() NULL error
In-Reply-To: <AC523039-F1EF-4FC4-96FB-EC21753AC3F0@soton.ac.uk>
References: <AC523039-F1EF-4FC4-96FB-EC21753AC3F0@soton.ac.uk>
Message-ID: <52FE7962.5070103@stsci.edu>

Can you provide a standalone example and data that reproduces the error?

This indicates that wcslib set an error flag on an operation but didn't 
actually set any information about the error.  This really shouldn't 
happen in normal usage except if there's some latent bug in wcslib or 
astropy.wcs...  but I'll need to be able to reproduce it to be sure.

Mike

On 02/14/2014 10:09 AM, frohmaier c. (cf5g09) wrote:
> Hi,
>
> When attempting to run all_pix2world() I get the following error:
>
> ERROR: RuntimeError: NULL error object in wcslib
>
> I cannot find any reference to this in the Astropy documentation. Does anyone know how I can resolve this?
>
> Cheers,
> Chris
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


-- 
                    _
|\/|o _|_  _. _ | | \.__  __|__|_|_  _  _ ._ _
|  ||(_| |(_|(/_| |_/|(_)(/_|_ |_|_)(_)(_)| | |

http://www.droettboom.com



From cf5g09 at soton.ac.uk  Sun Feb 16 06:49:49 2014
From: cf5g09 at soton.ac.uk (frohmaier c. (cf5g09))
Date: Sun, 16 Feb 2014 11:49:49 +0000
Subject: [AstroPy] all_pix2world() NULL error
In-Reply-To: <52FE7962.5070103@stsci.edu>
References: <AC523039-F1EF-4FC4-96FB-EC21753AC3F0@soton.ac.uk>
	<52FE7962.5070103@stsci.edu>
Message-ID: <9D70C517-5D76-4EEE-9FDA-B33841B78190@soton.ac.uk>

Hi Mike,

I?m using PTF data, here is an example image: https://www.dropbox.com/s/yc7lz51ar56a68f/PTF201203051940_2_o_62108_00.w.fits

My steps to reproduce the problem are:
>>> hdulist=fits.open('PTF201203051940_2_o_62108_00.w.fits')
>>> worldc=wcs.WCS(hdulist[0].header)
>>> pixcrd=numpy.array([[536.0,894.0]],numpy.float_)
>>> cords=worldc.all_pix2world(pixcrd,0)
ERROR: RuntimeError: NULL error object in wcslib [astropy.wcs.wcs]

Many thanks,

Chris

On 14 Feb 2014, at 20:15, Michael Droettboom <mdroe at stsci.edu> wrote:

> Can you provide a standalone example and data that reproduces the error?
> 
> This indicates that wcslib set an error flag on an operation but didn't 
> actually set any information about the error.  This really shouldn't 
> happen in normal usage except if there's some latent bug in wcslib or 
> astropy.wcs...  but I'll need to be able to reproduce it to be sure.
> 
> Mike
> 
> On 02/14/2014 10:09 AM, frohmaier c. (cf5g09) wrote:
>> Hi,
>> 
>> When attempting to run all_pix2world() I get the following error:
>> 
>> ERROR: RuntimeError: NULL error object in wcslib
>> 
>> I cannot find any reference to this in the Astropy documentation. Does anyone know how I can resolve this?
>> 
>> Cheers,
>> Chris
>> 
>> 
>> 
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> -- 
>                    _
> |\/|o _|_  _. _ | | \.__  __|__|_|_  _  _ ._ _
> |  ||(_| |(_|(/_| |_/|(_)(/_|_ |_|_)(_)(_)| | |
> 
> http://www.droettboom.com
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy



From ghang.naoc at gmail.com  Sun Feb 16 09:51:54 2014
From: ghang.naoc at gmail.com (gonghang.naoc)
Date: Sun, 16 Feb 2014 22:51:54 +0800
Subject: [AstroPy] how to determine whether a point was observed by hst ever?
Message-ID: <CABb23mscq_LH++Gkqw8qdsexfFp7jjDUTgUzTuicbmdfBprQcQ@mail.gmail.com>

hi,
If there is just one point, we can check stsci. How about many points?
I just need a yes or no.  Of course an observation log is even better.
Even we input a position and the output list is not null in stsci, there is
not necessarily archive data covered that point because of the search
radius and the shape of hst' fov.
Did anybody write a similar script before?   How do you check the archive
data? A web crawler is necessary?

Thank you.
hang
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From thomas.robitaille at gmail.com  Sun Feb 16 15:16:44 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Sun, 16 Feb 2014 21:16:44 +0100
Subject: [AstroPy] how to determine whether a point was observed by hst
	ever?
In-Reply-To: <CABb23mscq_LH++Gkqw8qdsexfFp7jjDUTgUzTuicbmdfBprQcQ@mail.gmail.com>
References: <CABb23mscq_LH++Gkqw8qdsexfFp7jjDUTgUzTuicbmdfBprQcQ@mail.gmail.com>
Message-ID: <CAGMHX_2qSdWYh2ygcOTbgx3+Bv2xmN8weKg+gbVM-Kdg-q1ZJA@mail.gmail.com>

Hi Hang,

You can query the HST archive from Python using the following URL:

http://archive.stsci.edu/hst/search.php?RA=12.2&DEC=13.1&radius=100&max_records=1000&outputformat=CSV&action=Search

modify RA, Dev, and radius as needed. I'm not sure what the latest
radius and maximum number of records is, but you could always try and
write a script that will run this for the whole sky by looping over RA
and Dec.

Cheers,
Tom


On 16 February 2014 15:51, gonghang.naoc <ghang.naoc at gmail.com> wrote:
> hi,
> If there is just one point, we can check stsci. How about many points?
> I just need a yes or no.  Of course an observation log is even better.
> Even we input a position and the output list is not null in stsci, there is
> not necessarily archive data covered that point because of the search radius
> and the shape of hst' fov.
> Did anybody write a similar script before?   How do you check the archive
> data? A web crawler is necessary?
>
> Thank you.
> hang
>
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>


From ghang.naoc at gmail.com  Sun Feb 16 22:20:45 2014
From: ghang.naoc at gmail.com (gonghang.naoc)
Date: Mon, 17 Feb 2014 11:20:45 +0800
Subject: [AstroPy] how to determine whether a point was observed by hst
	ever?
In-Reply-To: <CAGMHX_2qSdWYh2ygcOTbgx3+Bv2xmN8weKg+gbVM-Kdg-q1ZJA@mail.gmail.com>
References: <CABb23mscq_LH++Gkqw8qdsexfFp7jjDUTgUzTuicbmdfBprQcQ@mail.gmail.com>
	<CAGMHX_2qSdWYh2ygcOTbgx3+Bv2xmN8weKg+gbVM-Kdg-q1ZJA@mail.gmail.com>
Message-ID: <CABb23mu8qkKb-LKYuzVBoVoOdVt+rncofoQuJ9s1BGWf=HXB_A@mail.gmail.com>

hi,
Thank you. I tried one position with a same ra&dec&radius and it seems
there is a big difference between that url output and the stsci output.
The fits names are different. So I use observation time,but the time is not
the same at all either.

hang



On Mon, Feb 17, 2014 at 4:16 AM, Thomas Robitaille <
thomas.robitaille at gmail.com> wrote:

> Hi Hang,
>
> You can query the HST archive from Python using the following URL:
>
>
> http://archive.stsci.edu/hst/search.php?RA=12.2&DEC=13.1&radius=100&max_records=1000&outputformat=CSV&action=Search
>
> modify RA, Dev, and radius as needed. I'm not sure what the latest
> radius and maximum number of records is, but you could always try and
> write a script that will run this for the whole sky by looping over RA
> and Dec.
>
> Cheers,
> Tom
>
>
> On 16 February 2014 15:51, gonghang.naoc <ghang.naoc at gmail.com> wrote:
> > hi,
> > If there is just one point, we can check stsci. How about many points?
> > I just need a yes or no.  Of course an observation log is even better.
> > Even we input a position and the output list is not null in stsci, there
> is
> > not necessarily archive data covered that point because of the search
> radius
> > and the shape of hst' fov.
> > Did anybody write a similar script before?   How do you check the archive
> > data? A web crawler is necessary?
> >
> > Thank you.
> > hang
> >
> >
> >
> >
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > http://mail.scipy.org/mailman/listinfo/astropy
> >
>
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From mdroe at stsci.edu  Tue Feb 18 12:34:41 2014
From: mdroe at stsci.edu (Michael Droettboom)
Date: Tue, 18 Feb 2014 12:34:41 -0500
Subject: [AstroPy] all_pix2world() NULL error
In-Reply-To: <9D70C517-5D76-4EEE-9FDA-B33841B78190@soton.ac.uk>
References: <AC523039-F1EF-4FC4-96FB-EC21753AC3F0@soton.ac.uk>
	<52FE7962.5070103@stsci.edu>
	<9D70C517-5D76-4EEE-9FDA-B33841B78190@soton.ac.uk>
Message-ID: <530399B1.3080101@stsci.edu>

Indeed, there was an bug in propagating the error message back to Python 
in |astropy.wcs|.

A fix for that is now in this pull request:

https://github.com/astropy/astropy/pull/2106

As a workaround until this fix is merged into a release, you can 
explicitly call |.wcs.set()| on the |WCS| object after creating it 
(astropy 0.4 already does this implicitly anyway).

That reveals the actual error in the WCS header:

|astropy.wcs._wcs.InvalidTransformError: ERROR 6 in wcsset() at line 1562 of file cextern/wcslib/C/wcs.c:
PV1_5 : Unrecognized coordinate transformation parameter.
|

This is because the WCS specifies TAN projections, which don?t have any 
additional PV parameters, yet this header has them. I?ve seen this in 
headers generated by SCAMP before, and we have a fix this technically 
non-standard construction in this pull request (which will make it into 
astropy 0.4):

https://github.com/astropy/astropy/pull/1278

Mike

On 02/16/2014 06:49 AM, frohmaier c. (cf5g09) wrote:

> Hi Mike,
>
> I?m using PTF data, here is an example image: https://www.dropbox.com/s/yc7lz51ar56a68f/PTF201203051940_2_o_62108_00.w.fits
>
> My steps to reproduce the problem are:
>>>> hdulist=fits.open('PTF201203051940_2_o_62108_00.w.fits')
>>>> worldc=wcs.WCS(hdulist[0].header)
>>>> pixcrd=numpy.array([[536.0,894.0]],numpy.float_)
>>>> cords=worldc.all_pix2world(pixcrd,0)
> ERROR: RuntimeError: NULL error object in wcslib [astropy.wcs.wcs]
>
> Many thanks,
>
> Chris
>
> On 14 Feb 2014, at 20:15, Michael Droettboom <mdroe at stsci.edu> wrote:
>
>> Can you provide a standalone example and data that reproduces the error?
>>
>> This indicates that wcslib set an error flag on an operation but didn't
>> actually set any information about the error.  This really shouldn't
>> happen in normal usage except if there's some latent bug in wcslib or
>> astropy.wcs...  but I'll need to be able to reproduce it to be sure.
>>
>> Mike
>>
>> On 02/14/2014 10:09 AM, frohmaier c. (cf5g09) wrote:
>>> Hi,
>>>
>>> When attempting to run all_pix2world() I get the following error:
>>>
>>> ERROR: RuntimeError: NULL error object in wcslib
>>>
>>> I cannot find any reference to this in the Astropy documentation. Does anyone know how I can resolve this?
>>>
>>> Cheers,
>>> Chris
>>>
>>>
>>>
>>> _______________________________________________
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>> -- 
>>                     _
>> |\/|o _|_  _. _ | | \.__  __|__|_|_  _  _ ._ _
>> |  ||(_| |(_|(/_| |_/|(_)(/_|_ |_|_)(_)(_)| | |
>>
>> http://www.droettboom.com
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy

-- 
                    _
|\/|o _|_  _. _ | | \.__  __|__|_|_  _  _ ._ _
|  ||(_| |(_|(/_| |_/|(_)(/_|_ |_|_)(_)(_)| | |

http://www.droettboom.com

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From martinberoiz at gmail.com  Wed Feb 19 17:33:39 2014
From: martinberoiz at gmail.com (Martin Beroiz)
Date: Wed, 19 Feb 2014 16:33:39 -0600
Subject: [AstroPy] example on phot class on astropysics
Message-ID: <F165AFD4-FE79-42A7-BA6C-5D7D0F5F11C0@gmail.com>

Hello all,

I'm trying to do simple photometry on some images using the phot clases on astropysics. 
I read this page: 
http://pythonhosted.org/Astropysics/coremods/phot.html#astropysics.phot.PhotObservation

and I tried some simple calls like:

>>> import astropysics.phot as ap
>>> gs = ap.GaussianPointSpreadFunction()
>>> cent, sig = gs.fit(sc)

(Here sc is a 20x20 numpy array of float32's)

Does anyone have a simple example on how to do some aperture photometry or the profile of the star? I don't seem to find any tool to do that.

Also, 

>>> ie = ap.IsophotalEllipse(sc)
>>> ie.b

Gives the error: 
TypeError: Improper input: N=5 must not exceed M=4

ERROR: TypeError: Improper input: N=5 must not exceed M=4 [scipy.optimize.minpack]

for the same image, what could that be?



Thanks!
M.



From erik.tollerud at gmail.com  Thu Feb 20 20:08:02 2014
From: erik.tollerud at gmail.com (Erik Tollerud)
Date: Thu, 20 Feb 2014 20:08:02 -0500
Subject: [AstroPy] example on phot class on astropysics
In-Reply-To: <F165AFD4-FE79-42A7-BA6C-5D7D0F5F11C0@gmail.com>
References: <F165AFD4-FE79-42A7-BA6C-5D7D0F5F11C0@gmail.com>
Message-ID: <CAARXUwUyVU8C_Tc=8QaqxX2tjSLuomYA4GWe4J5JhPFXty+aNA@mail.gmail.com>

Hello Martin,

If you're looking for aperture photometry, I'd suggest photutils (
http://photutils.readthedocs.org/en/latest/photutils/aperture.html).
 That's where development will be in the future, and it's probably already
better for aperture photometry than astropysics has ever been or will be (I
can say that, because I'm the author ;).

If PSF photometry is more what you're looking for, you might try out
functionality that's due to get merge in photutils (
https://github.com/astropy/photutils/pull/26 , with a demo at
http://nbviewer.ipython.org/gist/adonath/6550989/PSFPhotometrySpitzer.ipynb
).

Hope that helps...



On Wed, Feb 19, 2014 at 5:33 PM, Martin Beroiz <martinberoiz at gmail.com>wrote:

> Hello all,
>
> I'm trying to do simple photometry on some images using the phot clases on
> astropysics.
> I read this page:
>
> http://pythonhosted.org/Astropysics/coremods/phot.html#astropysics.phot.PhotObservation
>
> and I tried some simple calls like:
>
> >>> import astropysics.phot as ap
> >>> gs = ap.GaussianPointSpreadFunction()
> >>> cent, sig = gs.fit(sc)
>
> (Here sc is a 20x20 numpy array of float32's)
>
> Does anyone have a simple example on how to do some aperture photometry or
> the profile of the star? I don't seem to find any tool to do that.
>
> Also,
>
> >>> ie = ap.IsophotalEllipse(sc)
> >>> ie.b
>
> Gives the error:
> TypeError: Improper input: N=5 must not exceed M=4
>
> ERROR: TypeError: Improper input: N=5 must not exceed M=4
> [scipy.optimize.minpack]
>
> for the same image, what could that be?
>
>
>
> Thanks!
> M.
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



-- 
Erik
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From matthewturk at gmail.com  Wed Feb 19 20:40:11 2014
From: matthewturk at gmail.com (Matthew Turk)
Date: Wed, 19 Feb 2014 17:40:11 -0800
Subject: [AstroPy] ANN: SciPy 2014 Conference, July 6th - 12th, Austin, TX!
Message-ID: <CALO3=5Fr=bcTQ8+LDS+sCteqK6TpW9Ng3vYvnuNzTs7t3Qrubg@mail.gmail.com>

Hello All!

I am pleased to announce that SciPy 2014, the thirteenth annual
Scientific Computing with Python conference, will be held this July
6th-12th in Austin, Texas. SciPy is a community dedicated to the
advancement of scientific computing through open source Python
software for mathematics, science, and engineering. The annual SciPy
Conference allows participants from all types of organizations to
showcase their latest projects, learn from skilled users and
developers, and collaborate on code development.

For more information please visit our website:
https://conference.scipy.org/scipy2014/

This year the conference has been extended to include an additional
day of presentations. During the presentation days SciPy is proud to
host the following event and talk types:

Keynotes
Expert Panels
Short Talks
Poster Presentations
Birds of a Feather Sessions

The full program will consist of two days of tutorials by followed by
three days of presentations, and concludes with two days of developer
sprints on projects of interest to attendees. This year, we are
excited to present a job fair for the first time!

Specialized Tracks

This year we are happy to announce two specialized tracks that run in
parallel to the general conference:

Scientific Computing in Education

Thanks to efforts such as Software Carpentry, the Hacker Within and
grassroots Python Bootcamps, teaching scientific computing as a
discipline is becoming more widely accepted and recognized as a
crucial task in developing scientific literacy. This special track
will focus on efforts to promote and develop scientific computing
education, as well as related topics such as reproducibility and best
practices for scientific computing.

Geospatial Data in Science

Python has become a core component of organiziing, understanding, and
visualizing geospatial data. This track will focus on libraries, tools
and techniques for processing Geospatial data of all types and for all
purposes -- from low-volume to high-volume, local and global.

Domain-specific Mini-symposia

Introduced in 2012, mini-symposia are held to discuss scientific
computing applied to a specific scientific domain/industry during a
half afternoon after the general conference. Their goal is to promote
industry specific libraries and tools, and gather people with similar
interests for discussions.

Mini-symposia on the following topics will take place this year:

Astronomy and astrophysics
Bioinformatics
Geophysics
Vision, Visualization, and Imaging
Computational Social Science and Digital Humanities
Engineering

Tutorials

Multiple interactive half-day tutorials will be taught by community
experts. The tutorials provide conceptual and practical coverage of
tools that have broad interest at both an introductory or advanced
level. This year, a third track will be added, which target
specifically programmers with no prior knowledge of scientific python.

Developer Sprints

A hackathon environment is setup for attendees to work on the core
SciPy packages or their own personal projects. Theconference is an
opportunity for developers that are usually physically separated to
come together and engage in highly productive sessions. It is also an
occasion for new community members to introduce themselves and receive
tips from community experts. This year, some of the sprints will be
scheduled and announced ahead of the conference.

Birds-of-a-Feather (BOF) Sessions

Birds-of-a-Feather sessions are self-organized discussions that run
parallel to the main conference. The BOFs sessions cover primary,
tangential, or unrelated topics in an interactive, discussion setting.
This year, some of the BOF sessions will be scheduled and announced
ahead of the conference.

Important Dates

March 14th: Presentation abstracts, poster, tutorial submission
deadline. Application for sponsorship deadline.
April 17th: Speakers selected
April 22nd: Sponsorship acceptance deadline
May 1st: Speaker schedule announced
May 6th, or 150 registrants: Early-bird registration ends
July 6-12th: 2 days of tutorials, 3 days of conference, 2 days of sprints

We look forward to a very exciting conference and hope to see you all
in Austin this summer!

The SciPy2014 Organizers


From martinberoiz at gmail.com  Fri Feb 21 12:33:20 2014
From: martinberoiz at gmail.com (martin)
Date: Fri, 21 Feb 2014 11:33:20 -0600
Subject: [AstroPy] example on phot class on astropysics
In-Reply-To: <CAARXUwUyVU8C_Tc=8QaqxX2tjSLuomYA4GWe4J5JhPFXty+aNA@mail.gmail.com>
References: <F165AFD4-FE79-42A7-BA6C-5D7D0F5F11C0@gmail.com>
	<CAARXUwUyVU8C_Tc=8QaqxX2tjSLuomYA4GWe4J5JhPFXty+aNA@mail.gmail.com>
Message-ID: <723C2AD0-191B-447D-BE06-35D9C7EB6EC0@gmail.com>

Thanks! this is what I was looking for.

On Feb 20, 2014, at 7:08 PM, Erik Tollerud <erik.tollerud at gmail.com> wrote:

> Hello Martin,
> 
> If you're looking for aperture photometry, I'd suggest photutils (http://photutils.readthedocs.org/en/latest/photutils/aperture.html).  That's where development will be in the future, and it's probably already better for aperture photometry than astropysics has ever been or will be (I can say that, because I'm the author ;).  
> 
> If PSF photometry is more what you're looking for, you might try out functionality that's due to get merge in photutils (https://github.com/astropy/photutils/pull/26 , with a demo at http://nbviewer.ipython.org/gist/adonath/6550989/PSFPhotometrySpitzer.ipynb).
> 
> Hope that helps...
> 
> 
> 
> On Wed, Feb 19, 2014 at 5:33 PM, Martin Beroiz <martinberoiz at gmail.com> wrote:
> Hello all,
> 
> I'm trying to do simple photometry on some images using the phot clases on astropysics.
> I read this page:
> http://pythonhosted.org/Astropysics/coremods/phot.html#astropysics.phot.PhotObservation
> 
> and I tried some simple calls like:
> 
> >>> import astropysics.phot as ap
> >>> gs = ap.GaussianPointSpreadFunction()
> >>> cent, sig = gs.fit(sc)
> 
> (Here sc is a 20x20 numpy array of float32's)
> 
> Does anyone have a simple example on how to do some aperture photometry or the profile of the star? I don't seem to find any tool to do that.
> 
> Also,
> 
> >>> ie = ap.IsophotalEllipse(sc)
> >>> ie.b
> 
> Gives the error:
> TypeError: Improper input: N=5 must not exceed M=4
> 
> ERROR: TypeError: Improper input: N=5 must not exceed M=4 [scipy.optimize.minpack]
> 
> for the same image, what could that be?
> 
> 
> 
> Thanks!
> M.
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> 
> -- 
> Erik

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From gr.maravelias at gmail.com  Tue Feb 25 09:34:20 2014
From: gr.maravelias at gmail.com (Grigoris Maravelias)
Date: Tue, 25 Feb 2014 16:34:20 +0200
Subject: [AstroPy] convert equinox issue with nicmos/radio data?
Message-ID: <530CA9EC.10002@gmail.com>

Hello to all!

A colleague of mine experiences a problem with astropy when she tries to 
plot a nicmos image combined with radio contours.
Although the scripts runs flawlessly with most objects, when it fails 
the error output is this:

ERROR: Exception: Cannot convert between equatorial coordinates for 
equinoxes j2000 and j2000 [aplpy.wcs_util]
Traceback (most recent call last):
   File "./nicmos.py", line 98, in <module>
     f.show_contour(a149, colors="black", 
levels=np.logspace(math.log10(sa[hrs]),math.log10(maxa[hrs]), 
num=10),linestyles=['--'],slices=[0,0],linewidths=1)
   File "<string>", line 2, in show_contour
   File "/Library/Python/2.7/site-packages/aplpy/decorators.py", line 
25, in _auto_refresh
     f(*args, **kwargs)
   File "/Library/Python/2.7/site-packages/aplpy/aplpy.py", line 916, in 
show_contour
     contour_util.transform(c, wcs_contour, self._wcs, filled=filled, 
overlap=overlap)
   File "/Library/Python/2.7/site-packages/aplpy/contour_util.py", line 
26, in transform
     output=(system_out, equinox_out))
   File "/Library/Python/2.7/site-packages/aplpy/wcs_util.py", line 213, 
in convert_coords
     raise Exception("Cannot convert between equatorial coordinates for 
equinoxes %s and %s" % (equinox_in, equinox_out))
Exception: Cannot convert between equatorial coordinates for equinoxes 
j2000 and j2000

Is there any idea why it fails ?

Best
Grigoris




From thomas.robitaille at gmail.com  Wed Feb 26 08:01:29 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Wed, 26 Feb 2014 14:01:29 +0100
Subject: [AstroPy] convert equinox issue with nicmos/radio data?
In-Reply-To: <530CA9EC.10002@gmail.com>
References: <530CA9EC.10002@gmail.com>
Message-ID: <CAGMHX_1HPj_4fu4NwNcDojnn9=p1kEuJ4LKqspH3gBmZHgPzkA@mail.gmail.com>

Hi Grigoris,

Could you send me the problematic FITS file and a short script to
reproduce the problem? (off-list) Once I have the files I can look
into it.

Thanks,

Tom (APLpy developer)


On 25 February 2014 15:34, Grigoris Maravelias <gr.maravelias at gmail.com> wrote:
> Hello to all!
>
> A colleague of mine experiences a problem with astropy when she tries to
> plot a nicmos image combined with radio contours.
> Although the scripts runs flawlessly with most objects, when it fails
> the error output is this:
>
> ERROR: Exception: Cannot convert between equatorial coordinates for
> equinoxes j2000 and j2000 [aplpy.wcs_util]
> Traceback (most recent call last):
>    File "./nicmos.py", line 98, in <module>
>      f.show_contour(a149, colors="black",
> levels=np.logspace(math.log10(sa[hrs]),math.log10(maxa[hrs]),
> num=10),linestyles=['--'],slices=[0,0],linewidths=1)
>    File "<string>", line 2, in show_contour
>    File "/Library/Python/2.7/site-packages/aplpy/decorators.py", line
> 25, in _auto_refresh
>      f(*args, **kwargs)
>    File "/Library/Python/2.7/site-packages/aplpy/aplpy.py", line 916, in
> show_contour
>      contour_util.transform(c, wcs_contour, self._wcs, filled=filled,
> overlap=overlap)
>    File "/Library/Python/2.7/site-packages/aplpy/contour_util.py", line
> 26, in transform
>      output=(system_out, equinox_out))
>    File "/Library/Python/2.7/site-packages/aplpy/wcs_util.py", line 213,
> in convert_coords
>      raise Exception("Cannot convert between equatorial coordinates for
> equinoxes %s and %s" % (equinox_in, equinox_out))
> Exception: Cannot convert between equatorial coordinates for equinoxes
> j2000 and j2000
>
> Is there any idea why it fails ?
>
> Best
> Grigoris
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From eebanado at uc.cl  Wed Feb 26 11:23:12 2014
From: eebanado at uc.cl (=?ISO-8859-1?Q?Eduardo_Ba=F1ados_Torres?=)
Date: Wed, 26 Feb 2014 17:23:12 +0100
Subject: [AstroPy] Lower(Upper)case astropy table columns
Message-ID: <CAE_d_sB1=cBFVhkLFTXXQ7rTK=oO+uV5EUKs99ZUUe+7kkzYMQ@mail.gmail.com>

Hi all,

is there a way to lower case the columns of a table? I have tables that
sometimes come with the uppercase and other lowercase keywords. By now I am
just using try/except but this gets messy when the number of columns is
large. I was expecting to exist something like:

table.colnames.lower()

Is there something like that? or how could I work this around

Thanks!

Eduardo Ba?ados

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

For example
from astropy.table import Table
import numpy as np

t = Table(arr, names=('RA', 'DEC', 'REDSHIFT'))
t['RA']
#<Column name='RA' unit=None format=None description=None>
#array([ 0,  3,  6,  9, 12])
#I can access the table by t['RA']
#but I need to lowercase the columns to access them as
t['ra']
#KeyError: 'ra'
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From Alexander.Conley at Colorado.EDU  Wed Feb 26 11:33:18 2014
From: Alexander.Conley at Colorado.EDU (Alexander Joseph Conley)
Date: Wed, 26 Feb 2014 09:33:18 -0700
Subject: [AstroPy] Lower(Upper)case astropy table columns
In-Reply-To: <CAE_d_sB1=cBFVhkLFTXXQ7rTK=oO+uV5EUKs99ZUUe+7kkzYMQ@mail.gmail.com>
References: <CAE_d_sB1=cBFVhkLFTXXQ7rTK=oO+uV5EUKs99ZUUe+7kkzYMQ@mail.gmail.com>
Message-ID: <0B8BFD6F-440A-4713-A04F-AF8620F1C035@colorado.edu>

for colname in t.colnames:
   t.rename_column(colname, colname.lower())

But if you need to be able to use -either- ?ra? or ?RA?
I don?t know a way.

Alex

On 26-Feb-2014, at 9:23 AM, Eduardo Ba?ados Torres <eebanado at uc.cl> wrote:

> Hi all,
> 
> is there a way to lower case the columns of a table? I have tables that sometimes come with the uppercase and other lowercase keywords. By now I am just using try/except but this gets messy when the number of columns is large. I was expecting to exist something like:
> 
> table.colnames.lower()
> 
> Is there something like that? or how could I work this around
> 
> Thanks!
> 
> Eduardo Ba?ados
> 
> -------------------------------------
> 
> For example
> from astropy.table import Table
> import numpy as np
> 
> t = Table(arr, names=('RA', 'DEC', 'REDSHIFT'))
> t['RA']
> #<Column name='RA' unit=None format=None description=None>
> #array([ 0,  3,  6,  9, 12])
> #I can access the table by t['RA']
> #but I need to lowercase the columns to access them as
> t['ra']
> #KeyError: 'ra'
> 
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy



From aldcroft at head.cfa.harvard.edu  Wed Feb 26 12:07:49 2014
From: aldcroft at head.cfa.harvard.edu (Aldcroft, Thomas)
Date: Wed, 26 Feb 2014 12:07:49 -0500
Subject: [AstroPy] Lower(Upper)case astropy table columns
In-Reply-To: <0B8BFD6F-440A-4713-A04F-AF8620F1C035@colorado.edu>
References: <CAE_d_sB1=cBFVhkLFTXXQ7rTK=oO+uV5EUKs99ZUUe+7kkzYMQ@mail.gmail.com>
	<0B8BFD6F-440A-4713-A04F-AF8620F1C035@colorado.edu>
Message-ID: <CAMtEP6zEiA64d-svnjga7Brq_3HrZxi--CtgJonopOCVQUP-kg@mail.gmail.com>

On Wed, Feb 26, 2014 at 11:33 AM, Alexander Joseph Conley <
Alexander.Conley at colorado.edu> wrote:

> for colname in t.colnames:
>    t.rename_column(colname, colname.lower())


> But if you need to be able to use -either- 'ra' or 'RA'
> I don't know a way.
>

It isn't possible with the current Table implementation.  It should be
possible to subclass Table (and probably Row, TableColumns) to do this, but
might not be entirely trivial.

- Tom



>
> Alex
>
> On 26-Feb-2014, at 9:23 AM, Eduardo Ba?ados Torres <eebanado at uc.cl> wrote:
>
> > Hi all,
> >
> > is there a way to lower case the columns of a table? I have tables that
> sometimes come with the uppercase and other lowercase keywords. By now I am
> just using try/except but this gets messy when the number of columns is
> large. I was expecting to exist something like:
> >
> > table.colnames.lower()
> >
> > Is there something like that? or how could I work this around
> >
> > Thanks!
> >
> > Eduardo Ba?ados
> >
> > -------------------------------------
> >
> > For example
> > from astropy.table import Table
> > import numpy as np
> >
> > t = Table(arr, names=('RA', 'DEC', 'REDSHIFT'))
> > t['RA']
> > #<Column name='RA' unit=None format=None description=None>
> > #array([ 0,  3,  6,  9, 12])
> > #I can access the table by t['RA']
> > #but I need to lowercase the columns to access them as
> > t['ra']
> > #KeyError: 'ra'
> >
> >
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > http://mail.scipy.org/mailman/listinfo/astropy
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
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From thomas.robitaille at gmail.com  Wed Feb 26 14:24:53 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Wed, 26 Feb 2014 20:24:53 +0100
Subject: [AstroPy] convert equinox issue with nicmos/radio data?
In-Reply-To: <530CA9EC.10002@gmail.com>
References: <530CA9EC.10002@gmail.com>
Message-ID: <CAGMHX_0WBT-L6dXUS_jC2cP54QZFQ=TGkwTp=gtyprDQFMUeig@mail.gmail.com>

Hi Grigoris,

(just replying to the list in case anyone has the same issue)

The issue was due to the fact that one image had the first axis be the
declination and the second the right ascension (as opposed to RA then
Dec). I have fixed it so that this is now properly taken into account
in APLpy. You can update with

git clone https://github.com/aplpy/aplpy.git
cd aplpy
python setup.py install

Let me know if this does not fix the issue. I did see another error,
but I think this is unrelated.

Cheers,
Tom


On 25 February 2014 15:34, Grigoris Maravelias <gr.maravelias at gmail.com> wrote:
> Hello to all!
>
> A colleague of mine experiences a problem with astropy when she tries to
> plot a nicmos image combined with radio contours.
> Although the scripts runs flawlessly with most objects, when it fails
> the error output is this:
>
> ERROR: Exception: Cannot convert between equatorial coordinates for
> equinoxes j2000 and j2000 [aplpy.wcs_util]
> Traceback (most recent call last):
>    File "./nicmos.py", line 98, in <module>
>      f.show_contour(a149, colors="black",
> levels=np.logspace(math.log10(sa[hrs]),math.log10(maxa[hrs]),
> num=10),linestyles=['--'],slices=[0,0],linewidths=1)
>    File "<string>", line 2, in show_contour
>    File "/Library/Python/2.7/site-packages/aplpy/decorators.py", line
> 25, in _auto_refresh
>      f(*args, **kwargs)
>    File "/Library/Python/2.7/site-packages/aplpy/aplpy.py", line 916, in
> show_contour
>      contour_util.transform(c, wcs_contour, self._wcs, filled=filled,
> overlap=overlap)
>    File "/Library/Python/2.7/site-packages/aplpy/contour_util.py", line
> 26, in transform
>      output=(system_out, equinox_out))
>    File "/Library/Python/2.7/site-packages/aplpy/wcs_util.py", line 213,
> in convert_coords
>      raise Exception("Cannot convert between equatorial coordinates for
> equinoxes %s and %s" % (equinox_in, equinox_out))
> Exception: Cannot convert between equatorial coordinates for equinoxes
> j2000 and j2000
>
> Is there any idea why it fails ?
>
> Best
> Grigoris
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From asishrocks95 at gmail.com  Wed Feb 26 23:58:00 2014
From: asishrocks95 at gmail.com (Asish Panda)
Date: Thu, 27 Feb 2014 10:28:00 +0530
Subject: [AstroPy] Project of gsoc 2014, sunpy
Message-ID: <CAMTAJMF2UzN6MifXWHUFV8NE7OhLGQB99-zzXxKnM-we5PNbrg@mail.gmail.com>

Hey all.
I am planning to do the project listed in sunpy as "re-implementation of
sunpy.wcs as sunpy.coordinate using astropy coordinate."
https://github.com/sunpy/sunpy/wiki/Gsoc-2014-ideas

They are also planning to take this new API into account that will be
implemented by you all soon.
https://github.com/astropy/astropy-APEs/pull/6

What would be a good place for me to start researching about it, as a
complete beginner?

Thanks!
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From gr.maravelias at gmail.com  Fri Feb 28 07:10:46 2014
From: gr.maravelias at gmail.com (Grigoris Maravelias)
Date: Fri, 28 Feb 2014 14:10:46 +0200
Subject: [AstroPy] convert equinox issue with nicmos/radio data?
In-Reply-To: <CAGMHX_0WBT-L6dXUS_jC2cP54QZFQ=TGkwTp=gtyprDQFMUeig@mail.gmail.com>
References: <530CA9EC.10002@gmail.com>
	<CAGMHX_0WBT-L6dXUS_jC2cP54QZFQ=TGkwTp=gtyprDQFMUeig@mail.gmail.com>
Message-ID: <53107CC6.2040300@gmail.com>

Hi Tom! Indeed this fixed the issue.

Thanks for the quick response.

Best
Grigoris

On 02/26/2014 09:24 PM, Thomas Robitaille wrote:
> Hi Grigoris,
>
> (just replying to the list in case anyone has the same issue)
>
> The issue was due to the fact that one image had the first axis be the
> declination and the second the right ascension (as opposed to RA then
> Dec). I have fixed it so that this is now properly taken into account
> in APLpy. You can update with
>
> git clone https://github.com/aplpy/aplpy.git
> cd aplpy
> python setup.py install
>
> Let me know if this does not fix the issue. I did see another error,
> but I think this is unrelated.
>
> Cheers,
> Tom
>
>
> On 25 February 2014 15:34, Grigoris Maravelias<gr.maravelias at gmail.com>  wrote:
>> Hello to all!
>>
>> A colleague of mine experiences a problem with astropy when she tries to
>> plot a nicmos image combined with radio contours.
>> Although the scripts runs flawlessly with most objects, when it fails
>> the error output is this:
>>
>> ERROR: Exception: Cannot convert between equatorial coordinates for
>> equinoxes j2000 and j2000 [aplpy.wcs_util]
>> Traceback (most recent call last):
>>     File "./nicmos.py", line 98, in<module>
>>       f.show_contour(a149, colors="black",
>> levels=np.logspace(math.log10(sa[hrs]),math.log10(maxa[hrs]),
>> num=10),linestyles=['--'],slices=[0,0],linewidths=1)
>>     File "<string>", line 2, in show_contour
>>     File "/Library/Python/2.7/site-packages/aplpy/decorators.py", line
>> 25, in _auto_refresh
>>       f(*args, **kwargs)
>>     File "/Library/Python/2.7/site-packages/aplpy/aplpy.py", line 916, in
>> show_contour
>>       contour_util.transform(c, wcs_contour, self._wcs, filled=filled,
>> overlap=overlap)
>>     File "/Library/Python/2.7/site-packages/aplpy/contour_util.py", line
>> 26, in transform
>>       output=(system_out, equinox_out))
>>     File "/Library/Python/2.7/site-packages/aplpy/wcs_util.py", line 213,
>> in convert_coords
>>       raise Exception("Cannot convert between equatorial coordinates for
>> equinoxes %s and %s" % (equinox_in, equinox_out))
>> Exception: Cannot convert between equatorial coordinates for equinoxes
>> j2000 and j2000
>>
>> Is there any idea why it fails ?
>>
>> Best
>> Grigoris
>>
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy


From r.tanuj at gmail.com  Fri Feb 28 14:21:17 2014
From: r.tanuj at gmail.com (Tanuj Rastogi)
Date: Sat, 1 Mar 2014 00:51:17 +0530
Subject: [AstroPy] Introducing Myself, GSoC '14
Message-ID: <CACSO+QUVT50rWZxaNzK25iMZO8YNrPtk14gzmxNsX4u5JvfV5w@mail.gmail.com>

Hi,
I am a 3rd year CS student from Thapar University, India.
I find your astropy project very interesting and have gone through the GSoC
'14 ideas list.

One of the ideas that I find interesting is:

*Implementing uncertainties in Quantity*

If possible, I would like to apply with a proposal for the same.
I have forked the astropy repository and am exploring the codebase and the
documentation related to
this idea (mainly *nddata* and *units* modules).

*This is what I have done so far:*
I have gone through the code in *astropy.units *module and
*astropy.nddata *module
and have gained some insight
into its working.
I have specifically understood the* NDUncertainty* and
*StdDevUncertainty*classes along with their usage in *NDData
*class
and the general structure of *NDData* class.
------
>From this preliminary study, my basic understanding of what I would have to
do is that:

1. Implement the uncertainty attribute in the *Quantity* class ( as an
object of *StdDevUncertainty* ).
2. Modify all operations on the *Quantity* class to ensure proper
propagation of uncertainty.
3. Possibly, work on expanding the *Uncertainty* class, for eg., writing
support for uncertainty with correlated variables.
------
Of course, I have not fully explored the *Quantity* class (or the
*astropy.units* module in general) and there might be some things
that I might be missing or getting wrong.
Plus, I am not sure about the importance(or urgency) of this project from
the organization's perspective and am open to ponder and work on other
ideas if/as
suggested by you.

Having said this, I would appreciate if you could guide me on how to
approach this idea further and building a proposal for the same.
I do have some specific questions:
1. What would be your advice on approaching this idea further?
    Should I:
    * Try to fix basic bugs listed in the github isuues page.
    * Spend time on understanding the codebase further to get a clearer
picture of what I have to do.
    * Focus on brushing up and reading some statistics and math related to
uncertainty, to form a more concrete and clear idea of how the uncertainty
      would propagate and how to implement it.
    * Any other general advice you would like to give.
2. What should be the scope of the proposal that I should aim for. For eg.,
should it include expanding or modifying the present Uncertainty framework.
------
I have a good background in Python. In my 3rd semester I did an online
course from Massachusetts Institute of Technology (through edx platform) on
'Introduction to Computer Science' which thought Python along with many CS
concepts. I also earned a certificate for completing it. I have used Python
extensively in a lot of coding contests.
In addition to this, I did a course on 'Introduction to Astronomy' from
Duke University (from Coursera).
I would be happy to answer any questions you might have.

Regards,
Tanuj Rastogi
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