Mailman 3 August 2002 - Edu-sig

Women, robots, and Python
by Douglas S. Blank Aug. 21, 2002

Aug. 21, 2002

Greetings! I've just joined this list, and have found the last couple of weeks' discussions to be right on target for me. I teach at Bryn Mawr College, an all women's school just getting a computer science (and cognitive science) program off the ground. The problems of gender and CompSci are complex ones, but ones that I think Python has a role in which to play. I hope that discussion continues here. We aren't ready to teach any courses in Python (yet) but the last project that I started is written in Python, called Pyro, for Python Robotics. It wasn't too long ago that planning a robotics system in an interpreted language would have seemed insane (and there are probably some that still think that!) But Python has turned out to work very well for our uses. One of the main goals was to encourage students to understand all aspects of the robotic control system, especially the "brains". we also wanted the system to be able to be used by "real" robotics researchers. So far, we have succeeded. The system is fast enough to control different types of robots (with lasers, sonars, and cameras) using simple Python control programs, to more complex ones written in Fuzzy logic, or neural networks... all in Python. You can download (or just checkout) Pyro at http://emergent.brynmawr.edu/wiki/?Pyro I look forward to conversations on intro teaching, gender issues, robots, and Python. Thanks, -Doug -- Douglas S. Blank, Assistant Professor dblank(a)brynmawr.edu, (610)526-6501 Bryn Mawr College, Computer Science Program 101 North Merion Ave, Park Science Bld. Bryn Mawr, PA 19010 dangermouse.brynmawr.edu

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re: Does edu-sig extend to Jython
by Arthur Aug. 20, 2002

Aug. 20, 2002

Kirby writes - >If you have just 3 parameters, that's six permutations right there. >Four parameters means 4!=24 possible function signatures. No Java >programmer want's to provide 24 ways of calling the exact same >function with the exact same parameters -- just in different order. >That would seem insane. If there is no good reason, its insane. If there is a good reason, it's 4 hours work that stands there as long as you want it to. (Or at least until 3.0 comes out). Not exactly like building houses out of soda cans - whatever the hell I mean by that. But as I say, I don't see what the good reason would be if I were working in Java. But I do think I know why I would be wanting to accomplish it in my exact circumstances. Will look closer, and back-off of it if it proves truly unwieldy. Art

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re: Girls, women and Programming (- and Python)
by Arthur Aug. 20, 2002

Aug. 20, 2002

>My wife thinks we should develop love-oriented programming.. >I would enjoy very much to hear your suggestions My wife's attitude is "why would anyone want to be a programmer." She considers it ministerial kind of work. Though she knows to be glad that there are people who actually want to do it. My own take, probably because I come from a family of strong women, is that this is much ado about nothing. My elder sister was an academic superstar, including near world class math aptitude. Near world class was not good enough for her, so she became a world class attorney - with a strong interest in women's issues, its true - and now is someone considered to be, let's say, important. Uncomfortable being specific. To me programming is like math, in that it has (or should have) zero gender related content. Not sure if I were a woman I would want to feel catered to, in any sense. Just the facts, thank you. Art

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Jython and VisAd
by Jason Cunliffe Aug. 20, 2002

Aug. 20, 2002

Jython showing up in very interesting edu-sig environments these days.. VisAd homepage http://www.ssec.wisc.edu/~billh/visad.html VisAD is a Java component library for interactive and collaborative visualization and analysis of numerical data. The name VisAD is an acronym for "Visualization for Algorithm Development". VisBio is a biological visualization tool designed to allow easy visualization and analysis of 4-D multispectral data--stacks of slices of biological data with multiple color values, animated across time. http://www.loci.wisc.edu/visbio/ Using Python with VisAD http://www.ssec.wisc.edu/~tomw/visadtutor/ Several small examples http://www.ssec.wisc.edu/~tomw/visadtutor/smallex.html Quick Reference to VisAD Python Interface Functions http://www.ssec.wisc.edu/~tomw/visadtutor/cheatsheet.txt ./Jason ______________________________________________ Jason Cunliffe [NOMADICS: Director art+design] Tel/fax: +1 718 422-1078 jasonic(a)nomadics.org N 43:00.000' W 074:31.875' ALT:1144 ft 84 Henry Street #3C Brooklyn NY 11201 USA

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re: Does edu-sig extend to Jython
by Arthur Aug. 20, 2002

Aug. 20, 2002

Kirby writes - >What I *don't* think any standard Java API is designed to >accommodate is simple parameter switching, i.e. to catch >(int a, int b) verus (int b, int a). Nor even (int a, float b) >versus (float b, int a) I don't pretend to know what is customary - but while int a, int b v. int b,int a won't fly I don't see why (int a, float b), (float b int a) wouldn't, and if it flies and helps - why not use it. But I agree with you in the sense that if I were in fact working in Java I would be less concerned about insulating a user from an API that might make argument order significant. The poor gal has to deal with a compile cycle, casting about of types, etc. and etc. in any case. They are programming, in the most formalistic sense of the word, whether they want to be or not. But in Python/VPython/PyGeo one is working in immediate mode. And when it comes to the point when a user is building geometric constructions by script, I would ideally like them to be thinking more as a geometer, then as a programmer. If 'them' is basically just me, it is no less true. Since there is no *geometric* reason for plane, line to be preferable over line, plane in finding an intersection, I would like there not to be an artificially imposed way it needs to be done. Basically just trying to get out of the way. Art

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re: Does edu-sig extend to Jython
by Arthur Aug. 20, 2002

Aug. 20, 2002

Dethe writes - >>Don't be too quick to take this off-list. I'm game. >While your situation is pretty specific, the general case of "why doesn't Python support feature >X of language Y" seems to be appropriate here. There are several >possible answers, all valuable in an educational context: >1) It does support X, but the python idiom looks like X() >.2) X isn't needed because of python feature Z >3) Python doesn't support X because X is a bad idea for such and such a >reason >4) Python doesn't support X, but you can do Z to simulate it I would think as to method overloading we are in the realm of 4). >In your case, if both Line and Point have methods getHalfIntersection(), >could you then have: >def intersection(first, second): > return first.getHalfIntersection() * second.getHalfIntersection() I get the gist of your suggestion, but the issue is pervasive and might overly tax my ingenuity. My current thinking is this: I need some testing of the arguments and some decent error reporting for inappropriate arguments, in any case. Right now you send a Line where the class needs a Plane, and somewhere down the pike you'll probably get a message about object x not having an attribute "normal" let's say -which Planes's have and Line's don't. For me, as a user, I pretty now where to go. For someone else, as a user, it would be a mystery. (Again, I am assuming this is a necessary byproduct of dynamic typing. I believe that Java would give an error message on construction that would be specific enough to allow me to forego some of this. OTOH, I went through the process far enough to understand some of what the dynamic typing of Python is *giving* me and *saving* me versus Java's typing methodology to know not to resent - more than just a little - what it might be costing me. I could elaborate with specifics, but won't) And in doing some real error catching and reporting on arguments, I would expect isinstance will come into play, and in doing it, it should not be very much additional burden to do it in such a way so that at least I can make argument order irrelevant. After that I guess I need to see where I am, and then take the more complex issues of this kind on a case by case basis - there probably is no one-size answer for all cases. Art

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re: Does edu-sig extend to Jython
by Arthur Aug. 20, 2002

Aug. 20, 2002

>If you want early failure, in an appropriate way, assert() is the way to >go. It would be fun to throw that sentence out to a nonprogrammer, without a hint as to its context, for a guess as to what was being said :) >What Java is giving is that it takes positional arguments and >demultiplexes for you based on type (and only on type). What python >gives you is that you can demultiplex based on name. Since python can >mix positional parameters and named parameters, and you can test type >yourself easily enough, it seems more powerful to me. Not disagreeing - but the customer is always right, and in this case customer Numero Uno is me, who refuses to work with named arguments in building his geometric constructions. Just interrupts the flow, he claims. As he is me I find it hard to disagree. Making life harder for me, the Developer - who must try to accomodate myself by working with position arguments alone. We - the whole crew of us - will get there (or close enough) eventually, I'm sure. Art

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re: Does edu-sig extend to Jython
by Arthur Aug. 19, 2002

Aug. 19, 2002

Jason writes - >>An excellent use of Jython is to provide CLI interface for Phil Burke's >>remarkable 'Jsyn' - Java Audio Synthesis API. As a general statement, obviously a beauty of Jython is the ability to access Java libraries and apps from Python. But certainly there is a "learning to program" aspect in addition.. >From my own experience - my exploration of Jpython led naturally into an exploration of Java. At some point the transition to writing pure Java came easily. The fact that I ended up returning to CPython almost surprised me. But it happens that VPython provided me with most of the 3d graphics capabilities I needed and had been looking to Java libraries to provide, and that I "think better" in Python - partly because it feel more finite and with less "magic" to it. What I miss most about Java, though, is one particular brand of magic - method overloading. >From the user prospective, for the kind of thing I am doing, it greatly simplified things. For example, I could provide for a class taking two arguments of different type to accept the arguments in either order. In Python I need to either use named argments, or handle it on initialization in ways that get to be complex, or use separate classes, or expect my user to learn or reference the acceptable order of argmuents. So far I have put the burden of the user. Since the only very active user happens to be me - it works out well enough. Probably less acceptable for this kind of app if it were to have a wider user base - especially where the novice is the intended audience. Advice being welcomed on this issue. Art

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Re: [Tutor] Girls, women and Programming (- and Python)
by Jason Cunliffe Aug. 17, 2002

Aug. 17, 2002

...some interesting reading, skills and attitude at http://www.linuxchix.org/ ./Jason ______________________________________________ Jason Cunliffe [NOMADICS: Director art+design] Tel/fax: +1 718 422-1078 jasonic(a)nomadics.org

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Re: [Edu-sig] Does edu-sig extend to Jython?
by Jason Cunliffe Aug. 17, 2002

Aug. 17, 2002

An excellent use of Jython is to provide CLI interface for Phil Burke's remarkable 'Jsyn' - Java Audio Synthesis API. "JSyn allows you to develop interactive computer music programs in Java. You can run them as stand-alone applications, or as Applets in a web page using the JSyn Plugin. JSyn uses native methods written in 'C' to provide real-time audio synthesis for Java programmers. JSyn can be used to generate sound effects, audio environments, or music. JSyn is based on the traditional model of unit generators which can be connected together to form complex sounds. For example, you could create a wind sound by connecting a white noise generator to a low pass filter that is modulated by a random contour generator." http://www.softsynth.com/jsyn/ http://www.softsynth.com/jsyn/slides/ http://www.softsynth.com/jsyn/examples/ http://music.columbia.edu/%7Ebrad/jlooch/ For Edu-Sig JSyn/Jython is another beautiful bridge between modeling, interactivity, and wave formation with sinaesthetic feedback. Lots for teacher/student/programmer to explore. When I raised the topic of Jython on the Jsyn list a while back, Robert Marsyani replied: "I did a little experimenting with jython/jsyn and liked it. It's nice to be able to instantiate 20 oscillators by typing in a 3-line loop and executing it right there..." I have not still used Jython for Jsyn yet as I've been really slow exploring Jython. But I don't know Java. Verbose, and the installation and changing terminology keeps me confused. But Java is potent and the APIs get better all the time like Python. Often when I install some cool new Java thing it I breaks some other cool Java thing. I am pleased to say that to date Jsyn has been very well-behaved. Have been put off diving in deeper with it for lack of Java skills. Jython offers the best of both worlds as far as I can tell. Yesterday in B&N was browsing the O'Reilly 'Jython Essentials' book. Seemed lucid, readable and helpful. Any recommendations about this or Jython for Java P rogrammers by Robert W. Bill ? ./Jason ______________________________________________ Jason Cunliffe [NOMADICS: Director art+design] Tel/fax: +1 718 422-1078 jasonic(a)nomadics.org N 43:00.000' W 074:31.875' ALT:1144 ft 84 Henry Street #3C Brooklyn NY 11201 USA

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