[Edu-sig] What to teach: sorting algorithms vs OOP?

[Wes Turner]

Optimization for real-world data.

Morse code is a good one; which leads to the entropy of real-world English
letters: how probable are the letters A, E, and Z? How probable is the
3-gram of letters 'AEZ'? A well-balanced tree could take this knowledge
into account and sparsely add 'nodes' without needing to rebalance as often.

Pairtree with hashes is an interesting real-world problem. Filesystems have
a max number of file entries per directory. A good cryptographic hash has
equal probabilities of e.g. hexadecimal character occurrence for each
digit: each digit character has an equal probability of following any other
digit.

Shannon used these probabilities for something; I can't remember what it
was?

One (TED-Ed) YouTube video I found mentioned sorting library books; what's
the fastest way?

Sorting is not strictly necessary for top-k N-dimensional optimization:
tracking high and low points doesn't require sorting the whole (then
ordered or partially ordered) set.

Here's an example from https://wrdrd.github.io/docs/consulting/data-science#
optimization :

Optimization⬅
https://en.wikipedia.org/wiki/Mathematical_optimization

Find local and global optima (maxima and minima) within an n-dimensional
field which may be limited by resource constraints.

# Global optima of a 1-dimensional list
points = [10, 20, 100, 20, 10]
global_max, global_min = max(points), min(points)
assert global_max == 100
assert global_min == 10

# Local optima of a 1-dimensional list
sample = points[:1]
local_max, local_min = max(sample), min(sample)
assert local_max == 20
assert local_min == 10

# A 2-dimensional list ...
points = [(-0.5, 0),
          (0,  0.5),
          (0.5,  0),
          (0, -0.5)]

https://en.wikipedia.org/wiki/Optimization_(disambiguation)
https://en.wikipedia.org/wiki/Metaheuristic
https://en.wikipedia.org/wiki/Receiver_operating_characteristic
http://rayli.net/blog/data/top-10-data-mining-algorithms-in-plain-english/
http://scikit-learn.org/stable/tutorial/machine_learning_map/
https://en.wikipedia.org/wiki/Firefly_algorithm

On Thursday, August 16, 2018, Tobias Kohn <kohnt at tobiaskohn.ch> wrote:

> I couldn't agree more!  Such interactive programmes are often so much more
> valuable than hours of talking (even though doing interactive programmes
> all the time will wear the students out -- as always, there is golden
> middle here ^_^).
>
> Another idea in that direction is to make two or three groups, and then
> have a little competition of who can sort a pile of post-its (or whatever)
> fastest.  And I would recommend to surprise the students.  Once they have
> learned how to sort numbers, say, give them post-its with picture of
> animals, say, or melodies, or whatever you fancy.  That forces them to
> think outside of the box, and suddenly computer science class becomes so
> much more meaningful and memorable!
>
> Yet another idea: how about sorting Morse code?  Usually, we get it sorted
> from 'A' to 'Z'.  But there are other ways, and before you know it, you are
> discussing trees...
>
> Cheers,
> Tobias
>
>
> Quoting kirby urner <kirby.urner at gmail.com>:
>
>
> I'm glad Tobias took the bull by the horns and didn't eschew  a deeper
> look into the sorting algorithms.
>
> As a big fan of animations, my reflex is to scour Youtube for graphical
> renderings of the different strategies, but then another thought crops up:
> lets get out of our seats and do choreography, Math is an Outdoor Sport!
> (PR poster). I should explain.
>
> The relationships between programming and scripting theater "programmes"
> (old spelling) are deep. Give each student a postit with a number and have
> them *enact* the sorting algorithm.  E.g. starting in a row, turn to person
> on your left (if there is one) and swap places if your postit number is
> higher...  have directors  and make a video.  Now choreograph (enact,
> dance) in a different way.
>
> Symphonies, plays, musicals, are so multi-track, so parallel, and yet we
> fail to exploit those intuitions sometimes.
>
> Let the Theater Department handle it, in consultation with CS.  Could go
> under the heading of "Unplugged".  Likely the Hobbits are already doing
> this in New Zealand (NZ has pioneered unplugged more than most, plus has
> Hobbits).
>
> Seriously, having lived in the Philippines where people routinely learn
> group dancing, I'm worried about only acting as teams in three capacities
> (a) cheerleader (b) athlete on the field (c) band.  Theater is being
> eliminated in favor of competitive sports.  Perhaps CS could come to the
> rescue and say "wait, we need Theater for our simulations".
>
> More cerebral team-based activities might go a long way towards fighting
> the stereotype that computer programmers  only live in artificially lit
> basements eating pizza.  That's a physically damaging lifestyle, nothing to
> do with writing code or even doing math.
>
> ===
>
> Regarding last night's tele-class (real time, zoom.us), I worked through
> "cloning a github repo" as the core exercise, a repeat from last week, then
> went through the process of updating a notebook live, and pushing the
> changes back to the repo.
>
> The repo was of course the one with yesterday's Jupyter Notebook about
> Ordering Polyhedrons by volume.
>
> https://github.com/4dsolutions/SAISOFT
>
> I tell them "cloning a github repo" is going to be important for when they
> want like a Jake Vanderplas tutorial, i.e. when they want to study a topic
> in more depth and the workshop is (A) on Youtube or similar service and (B)
> the workshop materials are free via github (a common enough pattern).
>
> I also reminded them how Google shares TensorFlow in the form of Colab
> exercises (Jupyter Notebooks).
>
> One students asked "R or Python, which is winning in Data Science"?
>
> My answer:  pandas is a relatively recent development and there's already
> lots of excellent curriculum based around R, which is likewise free / open
> source. The business world is rushing into Python because of DL / ML and so
> gains an R-like tool in the process, which enables better town-gown
> relations i.e. Harvard can talk to Facebook about Pytorch thanks to already
> teaching R in the stats department.
>
> In other words, it's not either/or, more like two communities forming a
> bridge via the common language of data science, which R and Python both
> reflect (as do some other languages / ecosystems, not aiming for
> comprehensivity here).
>
> Kirby
>
>
>
> On Wed, Aug 15, 2018 at 10:04 AM, Tobias Kohn <kohnt at tobiaskohn.ch> wrote:
>
>> *Hi Jurgis,*
>>
>
>
>
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