Mailman 3 February 2005 - Edu-sig

Uints in Python
by Jeff Sandys 23 Feb '05

23 Feb '05

If you are interested in doing units with Python, Unum by Pierre Denis is the package for you. It is compatible NumPy. http://home.tiscali.be/be052320/Unum.html >>> from unum.units import * >>> distance = 1 * MILE >>> distance.as(NMILE) 0.868974082073 [nmi] >>> distance.as(M) 1609.34 [m] >>> height = 4 * M >>> area = height * distance >>> area 6437.36 [m2] >>> area.as(ARE) 64.3736 [a] (an ARE is a metric acre) I have had some arguements with Pierre with his implementation of CELSIUS. His resonable arguement is that you usually don't multiply temperatures (degrees squared has no meaning) and you are mostly concerned with temperature differences. But I think that when you ask for the conversion with "as" it should say that 1 degree Kelvin is -272.16 degrees Centigrade. I will redo the "as" method to take care of this. >>> space = 2.5 * K >>> space 2.5 [K] >>> delta_space = .5 * CELSIUS >>> space - delta_space 2.0 [deg C] >>> space.as(CELSIUS) 2.5 [deg C] It is a cool package that I highly recommend for educational Python. Thanks, Jeff Sandys ___________________________________________________________________ Speed up your surfing with Juno SpeedBand. Now includes pop-up blocker! Only $14.95/month -visit http://www.juno.com/surf to sign up today!

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Re: [Edu-sig] Summary/Overview re Math Reform (my agenda -- Urner)
by ajsiegel＠optonline.net 23 Feb '05

23 Feb '05

----- Original Message ----- From: Kirby Urner <urnerk(a)qwest.net> Date: Monday, February 21, 2005 3:51 pm Subject: [Edu-sig] Summary/Overview re Math Reform (my agenda -- Urner) > > So I just started this thread on 'Calculus Mountain' on math-learn: > http://www.mathforum.com/epigone/math-learn/slingsamwang You're quite right AFAIAK. For myself, when the mountain looked liked Calc2, followed by Calc3,Calc4,Calc5,Calc6 I simply traversed down and found a more interesting looking mountain - with respect to my own sensiblities. Shame. My friend Felix Klein was not fully prescient here. Calc was just being introduced into mainstream curriculum at the time of his writing, and though this was not something that he himself was activiely behind, he seemed to be comfortable enough with it. > Basically, I'm arguing that we should evolve the computer science > track into > an alternative numeracy track, skirting calculus mountain yet > providingplenty of useful mathematics. > > This track will co-exist with, and compete with, the current > precalc-calc > track, which today monopolizes K-12 as the only gateway into > college level > technology tracks and careers. I've lost the trail of how it came to be that calc so thoroughly dominated math education once one gets past the fundamentals. But I am interested in that kind of thing and would like to pick up that trail. My own (out of fashion) sense, is that we will wondering one day how comp sci ed got bifurcated from math ed so suddenly, completely, dramatically and it appears - realistically - irreversibly. Integrated math/ comp. sci did threaten to revolutionize the math tract. I guess one theory: the revolution was averted by putting comp sci on its own tract. >From reaction here, it seems that technology folks in general are not uncomfortable with that solution. But I keep thinking that is because they rightly fear a comp sci track in the service to Calc1,Calc2,Calc3, Calc4,Calc5,Calc6 track, rather than one which leads a revolutionaized math track - developed with the computational power of the machine as a given. Or somethinf to that effect. Art

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RE: [Edu-sig] python satacad: class 6
by Arthur 21 Feb '05

21 Feb '05

> Indeed, thanks for the ammo (WMI-style). Could I bother you to > decorate that with more bibliographic tags (including page number), so > I can use it elsewhere as a formal citation? >Felix Klein >Elementary Mathematics From An Advanced Standpoint Geometry >Translated from the Third German Edition, Dover Publications, Copyright >1939 Oh yeah. All the quotes are from Klein's introduction - Pages 1 and 2. The book itself is some 200 dense pages, in 3 parts. I. The Simplest Geometric Manifolds II. Geometric Transformations III. Systematic discussion of Geometry and Its Foundations The resonance between the material in general, and the mathematics that has become second nature to anyone doing vector-based computer graphics, is clear. The material does go beyond it, into non-euclidian geometries and the Theory of the Imaginary. Though I had fairly recently come across something by Frederick Lundh of Python Imaging Library fame on using Python's native complex type as an efficient means of accomplishing graphics transformations in 2d. And even understood what he was talking about - for a change;). Art

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RE: [Edu-sig] python satacad: class 6
by Arthur 20 Feb '05

20 Feb '05

> Indeed, thanks for the ammo (WMI-style). Could I bother you to decorate > that with more bibliographic tags (including page number), so I can use it > elsewhere as a formal citation? Felix Klein Elementary Mathematics From An Advanced Standpoint Geometry Translated from the Third German Edition, Dover Publications, Copyright 1939 There is a separate book, which actually precedes it, on Algebra and Analysis, which I have but can't put my hands on at the moment. My wife likes to antique, and go to Estate sales. And I like to tag along, mostly looking at books. I picked this up and other good stuff at a sale in my area. There are and have long been a number of IBM research type facilities in our area, and these books were part of a collection of an IBMer that I was lucky enough to come across. Art

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RE: [Edu-sig] python satacad: class 6
by Arthur 20 Feb '05

20 Feb '05

> From: Kirby Urner [mailto:urnerk@qwest.net] > > From: Arthur [mailto:ajsiegel@optonline.net] > > And what Klein prescribes in the end sounds much like a primer on the > > underlying mathematics and ideas which we now know as the fundamentals > of > > computer vector graphics. Except that we tend to know these ideas, and > > teach them, out of the their historical and intellectual context. > > Yeah, I wondered if you were referring to Quaternions and see from your > concluding quote that you were. A good deal more to it than that. I am presenting Klein's ideas, not my own. So I will indulge myself by allowing myself some long quotes from the introduction to Volume II of his lectures at a summer teachers' colloquium, on Geometry - as I am not aware of this material up anywhere on the Web. """ ...I shall draw attention more than is usually done to the historical development of the science, to the accomplishments of the great pioneers. I hope, by discussions of this sort, to further, as I like to say, your general mathematical culture: alongside of knowledge of details, as these are supplied by the special lectures, there should be a grasp of the subject-matter and of historical relationship """ While Klein's ideas, they are ideas to which I prescribe. And I am proposing Klein himself, now, as such a pioneer. And noticing the vacuum of historical context that seems to prevail when approaching a subject like computer graphics and its mathematical underpinnings. To some of us, that historical context is perhaps its most engaging aspect. And while I am not asking that those of us with such a sensibility be allowed to dominate the proceedings, allowing this sensibility a sense of inclusion in those proceedings would seem to be to everyone's benefit. More Klein -- """ I advocate here, as always in such general lectures, a tendency which I like best to designate by the phrase 'fusion of arithmetic and geometry' - meaning by arithmetic, as is usual in the schools, the field which includes not merely the theory of integers, but also the whole of algebra and analysis. """ Klein is advocating this a half century before the developments that brought us the computer screen. The ability now to actualize and enliven - "not be dull" - this approach having been enhanced dramatically by these developments. And other than some pockets of practice in some Saturday academies ;) , largely ignored - as far as I can tell. More Klein - """ It has long been the custom in the schools as well as the university, first to study the plane and them, entirely separated from it, the geometry of space. On this account space perception, which we possess originally, is stunted. In contrast to this the 'fusionists' wish to treat the plane and space together, in order not to restrict our thinking artificially to two dimensions. """ Bucky and Klein seem to be on the same page, here. More Klein - """ Last semester I endeavored always to enliven the abstract discussions of arithmetic, algebra, and analysis by means of figures and graphic methods, which bring the things nearer to the individual and often make clear to him, for the first time, why he should be interested in them. Similarly I shall now, from the beginning, accompany space perception, which of course, will hold first place, with analytic formulas, which facilitate in the highest degree the precise formulation of geometric facts. """ IOW, the pictures aren't effective without the analytics, and vice versa. What this means to me, among other things, is "code as text". Something like PyGeo, for example, is - IMO - *only* interesting as an Open Source project, with the underlying analytics exposed. I could actually gone on a bit more, but this is getting out of hand in terms of length.... Art > > As it happens, the "more fully developed vector class" I was describing is > pretentious in just this way: if you multiply by a scalar, the vector > elongates or shrinks, like any good little vector. But if you try to > multiply by another vector, well then, both suddenly become quaternions at > that point -- though the result is returned as a vector. > > def __mul__(self, other): > """ > Might be just scalar multiplication, but if the arg is another > vector, let's go through the motions of quaternion * quaternion > """ > if type(other) == type(self): # treat mul as quaternion mul > # (v1 x v2) + (s1*v2) + (s2*v1) > newv = self.cross(other) + (self.s * other) + (other.s * self) > # s1*s2 - v1.v2 where s1 is self.s, v1 is self.v > newv.s = (self.s * other.s) - self.dot(other) > return newv > > if type(other) in [type(1.0), type(1)]: # or do scalar mul > return Vector3d(self.x * other, self.y * other, self.z * > other) > > __rmul__ = __mul__ > > http://www.4dsolutions.net/satacad/pytools/ -- see vector.py > > But I didn't get into this at all with the kids today. > > There's some excellent book on the history of vectors, one of those Dover > books -- talks about how the Gibbs-Heaviside approach gradually took hold > and that's what we generally taught in the 1900s. But computer gaming > helped quaternions make a come back. I used to post about this stuff > quite > a bit -- buried in the Math Forum archives probably. > > Yeah, here's the book, listed in the bibliography on that Quaternions page > at MathWorld: > > http://www.amazon.com/exec/obidos/tg/detail/-/0486679101/ > > Kirby >

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Re: [Edu-sig] Easy to use GUI
by Laura Creighton 18 Feb '05

18 Feb '05

In a message of Wed, 16 Feb 2005 02:43:23 EST, Nicholas Wheeler writes: >I would suggest AnyGUI. http://anygui.sf.net. It's a fairly simple GUI/fr >ontend. > Anygui is unfinished, and unlikely to be finished in the foreseeable future. There are many bugs left. Pythoncard is designed to fill the niche you are looking for, but I still prefer tkinter myself. Laura

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Re: [Edu-sig] Re: (financial calculation) - using units
by Laura Creighton 18 Feb '05

18 Feb '05

I think what you want is the traits package from SciPy (from Enthought). Paper here: http://python.fyxm.net/pycon/papers/traits.html Unfortunately, the code has moved, and I don't know where it has gone. Laura In a message of Tue, 15 Feb 2005 21:51:34 +0100, Christian Mascher writes: <snip> >I think as a physicist, don't know how they do it in finances. > >BTW, how does one express units of measure in Python/programming? >Calculations in applications aren't just about numbers. For instance, >how could one express equations like > 10000 cm^2 == 1 m^2 > 1000 g == 0.001 t >in a programming language? Another point would be the inclusion of a >measure of accuracy: >For a physicist or engineer > 1 cm != 1.00 cm >because the first could be 0.9 cm, the second couldn't, beeing more >accurate. > >Greetings, > >Christian

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New Functional Geometry
by ajsiegel＠optonline.net 17 Feb '05

17 Feb '05

Patrick Logan's weblog, digested on PlanetPython, points to what seems to be a very interesting treatise on geometry and functional programming: http://patricklogan.blogspot.com/2005/02/new-functional-geometry.html There seems to be some consensus, or at least general interest, in graphics programming as a means to some ends in an educational setting. Apple is at 88 this morning. On pace. So while I have unilaterally decided my stock is high, I am composing in my head a short manifesto on the subject of graphics programming in an educational setting - on why some general consensus on this makes so much sense, and how it might be put in some historical context and given more weight. The central figure in my thinking being Felix Klein. http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Klein.html Hope to have something up on this over the weekend. Art

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Easy to use GUI
by florian＠reichl.net 16 Feb '05

16 Feb '05

Hello everybody, I'm looking for a GUI that can be easily used by my students (and by me, of course ;-) That means that I'm looking for a GUI that * does not have to be powerful * shall have some easy to use "components" like text fields and buttons * that is easy to use for SMALL in school projects I'd would be very happy with some recommendations. Some code examples would be perfect. Thanks a lot for your support! Best regards, Florian

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Re: (financial calculation) - using units
by Christian Mascher 16 Feb '05

16 Feb '05

> def future_value(iday,cday,ivalue,cvalue,years): > days_invested=(cday-iday).days > year_periods=365/days_invested Bothered me (too), the year_periods should be of a time-dimension. duration_in_years=days/365 > annualized_rate = math.log(cvalue/ivalue)*year_periods ^ The rate is _per_ time-unit, so I would put the / here. Result remains the same of course. I think as a physicist, don't know how they do it in finances. BTW, how does one express units of measure in Python/programming? Calculations in applications aren't just about numbers. For instance, how could one express equations like 10000 cm^2 == 1 m^2 1000 g == 0.001 t in a programming language? Another point would be the inclusion of a measure of accuracy: For a physicist or engineer 1 cm != 1.00 cm because the first could be 0.9 cm, the second couldn't, beeing more accurate. Greetings, Christian

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