Mailman 3 December 2008 - Edu-sig

music:piano :: math:laptop ?
by kirby urner Dec. 16, 2008

Dec. 16, 2008

Edward Cherlin's insistent pointing to the XO is helping turn some wheels on my end... Way cool that Gibson Guitar was a sponsor of OSCON that time, shows how geeks are being seen from a Nashville angle: have laptop will travel, the solo musician model, except we also form bands. Really, so many analogies, between musicians and coders. What calculators, slide rules before 'em, have gotten us used to, is this idea that mathematics comes with devices, gizmos, more than just chalk or pencil. We need machinery! (a slide rule has moving parts, c'mon). What's interesting is how reluctant the marketing groups have been, to link their brands to something so Buck Rogers and futuristic as the XO, or even to the basic idea of giving kids laptops. It has all the elements: breakthrough technologies, hero developers (many genders and ethnicities), adorable children, cool interface... you'd think the cereal companies would be all over it, giving kids something to marvel at while crunching on wholesome grains. How about we start a campaign among tweens and teens called "Where's My Laptop?" Let's encourage that sense of entitlement we get listening to R0ml, who says gnu math, CP4E, computer literacy (lots of words for it) is what in the old days would be called "basic rhetoric". To participate in civic life, you needed to know how to structure an argument, defend a position. Well, you still need those skills, but you also need that laptop. How else do you expect to patch in, participate in the life of democracy. What do we want? Laptop! When do we want it? Now! Kirby

3 3

interactive python tutorial online (as tryruby)
by Jurgis Pralgauskis Dec. 15, 2008

Dec. 15, 2008

Hello, it would make python more attractive, if there would be possibility to try it online like ruby has http://tryruby.hobix.com maybe this could be made with jython , http://code.google.com/p/epy/ or crunchy on GAE how difficult it would be to have a secure thing, for people to get interactive intro about python identation and list manipulation magic :) ? -- Jurgis Pralgauskis tel: 8-616 77613; jabber: jurgis(a)akl.lt; skype: dz0rdzas; Don't worry, be happy and make things better ;)

4 6

Fwd: The 'Certified' Teacher Myth (long)
by kirby urner Dec. 15, 2008

Dec. 15, 2008

I'm forwarding this, enqueued with Math Forum moderators, as it gives some background perspective of potential utility to edu-sig subscribers, plus indirectly expresses my gratitude to Stef Mientki for his promising project. If you're embroiled in USA "math wars" at all and want to do background reading on this thread, here's a link: http://mathforum.org/kb/thread.jspa?threadID=1869138&tstart=0 I'd recommend staying blissfully ignorant of a lot of it though, lest you get caught up in dinosaur flavors of "should we allow calculators in math class?" kinds of debates (nothing at all about computer languages), angry mud slinging that's been going on for decades and going nowhere (lots of energy sinks, time sucks, not worth your attention). You may wonder why I bother to comment then, on Michael's mud-slinging (appended). As I mentioned in a follow-up: """ I'll fix and upload to edu-sig, in case Math Forum management decides not to archive publicly -- should go somewhere, world-readable, given my marketing angle -- Grunch isn't Michael's to spin, at least not all by himself. I have my investments to protect. """ For those with no idea what "Grunch" means (esoteric!), here's another Math Forum thread you might find edifying in this regard: http://mathforum.org/kb/thread.jspa?threadID=1866451&tstart=0 If you heard my talk at Chicago Pycon last year, or watched it on YouTube or ShowMeDo, you know that I talk about Fuller a lot -- a part of my (Quaker brand) futurism. Kirby ---------- Forwarded message ---------- From: kirby urner <kirby.urner(a)gmail.com> Date: Sun, Dec 14, 2008 at 11:06 AM Subject: Re: The 'Certified' Teacher Myth To: Michael Paul Goldenberg Cc: math-teach(a)mathforum.org, Richard Tchen, Haim, Wayne Bishop I haven't been following math-teach closely of late, don't think spitting in anyone's face, Haim's included (a mask), is going to solve the problems of Grunch being semi in control of world affairs, Grunch being Fuller's psychological projection (into American literature) of the phenomenon of wholesale globalization. If you're at all curious about my focus these days, aside from K-mods in the enneacontahedron (per geometry-pre-college, a different Math Forum list), I'm getting input from my peers re my upcoming 'Python for Teachers' in Chicago next spring. In particular, I've been looking for ways to integrate the VPython window, for spatial geometry, vectors and so on, with the shell and editing environments. Just yesterday, I learned of a breakthrough in this regard thanks to Google's Summer of Code program, a way of bringing strong coders into positions better able to benefit a larger population. Here's a screen shot of overlapping windows with VPython's one of them (spatial geometry lesson): http://www.flickr.com/photos/17157315@N00/3105638687/sizes/o/ Here's a screen shot of a new project-based IDE (integrated development environment) with VPython just one more display panel, surrounded by editing surfaces (modeling a hospital ER): http://www.flickr.com/photos/17157315@N00/3105561953/sizes/o/ I've already informed my edu-sig friends (a list in Python Nation), of my intent to showcase the latter as a part of my discussion, even if only in slide format. Certified teachers from the Chicago area are invited to this workshop, but mostly we're pandering to private sector geeks, thinking once they get out of high school, they'll go directly into corporate training programs, a lot of 'em, bypassing college until later maybe. Many will start in these programs even before finishing high school, as a bridge to some future position. Tuitions are really high right now, out of step with the ambient culture, especially in light of how far behind the times your average PhD has become (in just about any field you care to mention). Silicon Forest needs people, can't afford to sponsor these pipelines that no longer work for us. So as you can see, the whole thing about "certification" is kind of a side issue. In the private sector, we have our own way of designing a meritocracy, aren't looking to teacher unions for direction, not our culture. Kirby Urner grunch.net On Sun, Dec 14, 2008 at 10:42 AM, Michael Paul Goldenberg wrote: << SNIP >> > As we prepare for what well may another world-wide depression thanks to the > GRUNCH of the giants that Haim doesn't want to discuss here (we're supposed > to believe that it's teachers' unions that got us where we are, I suppose), > we should be spitting in the faces of people like Haim and their > self-serving, utterly bankrupt views and policies.

2 2

fracgen.py
by Charles Cossé Dec. 15, 2008

Dec. 15, 2008

Hi All, The recent discussion regarding fractions compelled me to dig-up a fraction problem generating script I wrote a couple years ago and post it in case anyone has use for it. The purpose of the script is to generate algebraic fraction problems. It might also make a decent programming assignment to come up with such an algorithm. Just run it and you'll get 100 good problems dumped to your screen. Change the 2 parameters in the __main__ to adjust number generated and maximum denominators to use. I've never looked at Fraction.py, so no idea how this compares or relates, but don't think there's any similarity. Anyway, FWIW here it is (attached). All the best to everyone, Charlie -- AsymptopiaSoftware|Software@theLimit http://www.asymptopia.org

1 0

computer algebra
by kirby urner Dec. 15, 2008

Dec. 15, 2008

So I've been yakking with Ian (tizard.stanford.edu) re the new fractions.py, installed in Standard Library per 2.6, saw it demoed at a recent user group meeting (PPUG). Python's __div__ is similar to Mathematica's computer algebra notion of division in that you're free to divide any type by any type, providing this makes any algebraic sense, using a kind of liberal duck typing. What I mean by that is __div__ by itself doesn't pre-specify anything, so if there's a meaningful way to deploy the division operator between arguments A, B, then go ahead and do it, write you code accordingly. In Java, we could write __div__ in all different ways depending on valid type permutations (not that Java has operator overloading, just stricter typing at write time means you've gotta post "guards at the gate" in your methods). Python, with late binding, duck typing, won't post guards, but you'll still need to write algorithms capable of sorting out the possibilities. Maybe the user throws you a matrix? Has an inverse. OK, so __div__ makes some sense... fractions.py in contrast, implements the narrow Q type, the rational number, defined as p / q where p, q are members of the set integers. One could imagine a Fraction class that eats two complex numbers, or two Decimals. Computer algebra attaches meaning here, as in both sets we're able to define a multiplicative identity such that A / B means A * B**(-1) i.e. A * pow(B, -1) i.e. A * (1/B). So the results of this operation, Fraction(A, B), might be some object holding the Decimal or Complex result. In generic algebra, everything's a duck, although conversion between types is possible (yes, that sounds nonsensical). fractions.Fraction, on the other hand, barfs on anything but integers, isn't trying to be all divisions to all possible types, isn't pretending this is Mathematica or a generic CAS. Note that I'm not criticizing fractions.py in any way, am so far quite happy with it. I'm simply drawing attention to some fine points. Related: When I went to all the trouble to compose two functions, f and g, using __mul__, I'd get comments like: but the "open oh" (another symbol) is the "composition operator" i.e. "you're only using * because ASCII doesn't include the 'open oh'". However, I was making a different point: that in group theory math texts, we're proud to use "regular" multiplication and division operators for such operations as "compositions of functions" because we're thinking __mul__ and __div__ have that generic meaning -- we neither need, nor want, the proliferation of symbols the "open oh" people think we must need. Note that by "open oh" I'm not talking about "big oh", a different notation that I don't think is redundant, agree with Knuth that if your calculus book doesn't include it, you're probably in one of those computer illiterate schools (ETS slave, whatever). Kirby

4 9

more Mathy Python...
by kirby urner Dec. 14, 2008

Dec. 14, 2008

FYI... http://www.tiac.net/~sw/2008/10/Hilbert/ (I like that they're called Hilbert *curves*) Kirby w/ thx to David Koski (geometer) for alerting me.

1 0

Thoughts about IDLE
by kirby urner Dec. 14, 2008

Dec. 14, 2008

Per very early in the edu-sig archive, I've always found IDLE both necessary and sufficient for most of my teaching needs, whereas in development I've used Vim (which I suck at), random editors and tools, less Eclipse than you might think, Wing. However, for quick scripts, IDLE works on the job as well, especially in Akbar font. What frustrates me in class though, is I'll get low on the projected screen, having entered a bunch of session variables, identified a lot of stuff, and then I'm sort of stuck to the lower edge, unable to wipe to the top and/or mouse blank command line to the top (drag operation). What's great about IDLE over say IPython is how mouse friendly it is, so easy to dive-bomb into a function def 100 lines back in time and bring it down (into the present), for revisions. You'll understand why I'm so comfortable with this approach if you understand my heritage as a dBase programmer. I think some newcomers to snake charming might be surprised how many of us came up through the pre open source ranks using xBase, which at one time Microsoft touted as the third of three pillars, VB and C/C++ the other two. Those were the bad old days before Unix swept the world by storm in the form of GNU Linux and we got access to true agiles. But not everything about those days was a waste of time. We couldn't have gotten "here" without some kind of "there" there. I think the future of IDLE (if I may speculate idly) will involve getting those plug-ins for non Latin-1 keyboards to drive iconic glyph-making on screen. As to Python itself, I've been wondering allowed whether __op__ = [klingon symbol] would be too terrible, or some other mechanism for opening the operator overloading mechanism to arbitrary Unicode symbols, without proliferating the number of special names in some out of control fashion (i.e. you don't want a __[symbol]__ for each possible symbol we might be tempted to repurpose). Perhaps the more attractive option, consistent with my disdain for "open oh" in place of __mul__, would be to restrict to these few operators, and suggest developers disabuse themselves of the notion that "more is better" in the case of operators to overload. Not only do you not *need* more than but a few (given how generic their capabilities -- as Guido just pointed out, you can pervert / to implement * if you care to, or just go __mul__ = __div__) but you should curb your *want* for that many. Think of your readers for a change. I'd be interested in what other teachers are doing when it comes to projecting Python in front of the class and rattling stuff out in a shell (not just showing scaffolding). When we get low on the screen, kids in the back have a harder time seeing. Yet we want that dBase-style chronology (characteristic of most shells, bash included) and mouse friendliness, something more like a canvas, less like a teletype. Finally, as someone with bookkeeping heritage, I like shells which "preserve mistakes" in the sense of keeping transactions on file, almost like patches and diffs in a version control system. You don't want to be able to "change the past in the past" once you've got a time sequence going, as that's not reflective of real time experience, so breaks the metaphor. If you had a typo at 2:30 PM, just copy it down to 3:00 PM and edit it, don't pretend you got it right the first time. IDLE is like that. Kirby

3 4

synthetic division
by michel paul Dec. 14, 2008

Dec. 14, 2008

On Friday we were studying synthetic substitution/division in Algebra 2. After going through the algorithm and after showing through factoring why it worked, I had them look at this code: def evaluate(polynomial, x): value = 0 for coefficient in polynomial: value = value*x + coefficient return value *polynomial *is a list of coefficients. This algorithm is identical to the factoring analysis I showed them. To then create the function 'divide' is a simple matter of returning a list of coefficients rather than one final value. This 'concept map' shows exactly the same thing as the diagram in our text, but it would be even more accurate to initialize *value* as polynomial[0] and to then make the for-loop 'for coefficient in polynomial[1:]', but I thought that in an environment where programming in math classes is still considered something alien, the indexing might cause some silly grade-anxiety reactions. How sad that this has to be an issue. But I figure that for the kids that are interested, and there are some, looking at indexing and splicing might be enticing. This has been my experience - looking at math concepts I have long taken for granted and thinking about how to express them in computational form as interacting functions/classes has shed new light on my own understanding. I can't help think that this would be invaluable for education. - Michel

1 0

teaching about privacy
by kirby urner Dec. 12, 2008

Dec. 12, 2008

Here's a way of giving students more of a sense of Python's "privacy layers". We're obviously drawing on experience with signage, various prohibitions likely already tuned in, e.g.: http://www.flickr.com/photos/17157315@N00/3051792354/ Here's the diagram: class Snake: def __init__(self): # birth method, use triggering syntax: newsnake = Snake() pass def _DontTouchMe(self) # authorized personal only (for maintenance, janitorial, internal use) pass def __YouShouldntHaveDoneThat(self) # keep out: actively discourage tourists, outsiders pass For those into American history, there's also this connotation (thanks to the snake imagery): http://images.google.com/images?gbv=2&hl=en&safe=off&q=%22don%27t+tread+on+… However, we should balance these strident (commanding) remonstrations with simple reminders about *why* we might want privacy. A lot of it has to do with retaining developer freedoms to change implementation, without changing the "user experience" i.e. the API, i.e. the "exposed" or "exported" methods are safe to rely on, but we have "under the hood" code we might want to rip out and replace, not the business of our clients. Privacy protections communicate where it's important *not* to "put your weight" e.g "place a dependency" on something. In cartoon terms, we might show a rickety bridge over a ravine, like in Indiana Jones: "Not safe to put your full weight on this board" is another meaning of __KeepOff. "Snake as potentially live wire" might be a good way to package this meme (curriculum segment). We also need to explain about munging (mangling). Kirby

1 0

Re: [Edu-sig] Programming in High School
by Daniel Ajoy Dec. 11, 2008

Dec. 11, 2008

On Wed, 10 Dec 2008 13:19:45 -0500, <edu-sig-request(a)python.org> wrote: >> But the criteria of "relevant problems, easily solved with a quickie >> program" is tough to meet. Solving a Max Problem Using Logo http://gsndev.org/archives/logo-l/1098/msg00085.html http://gsndev.org/archives/logo-l/1098/msg00097.html http://gsndev.org/archives/logo-l/1098/msg00104.html (the pictures are here http://neoparaiso.com/logo/problema-de-maximizacion.html ) Another one is: Calculating the MCD and MCM Another one is finding solutions of equations using bisection. And another point is that some problems cannot be solved using algebra or trig. I believe this is one: http://neoparaiso.com/logo/problema-triangulos.html It asks the student to determine the values of the segments a and b. Daniel

2 1