At 03:31 PM 4/18/2001 -0400, you wrote:

From: "Kirby Urner" <pdx4d@teleport.com>

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I've taught my polyhedra to display themselves in .m format, via a lg3d.py module, so now I can provide browsers with interactive views such as found at:

http://www.inetarena.com/~pdx4d/ocn/lvmviews.html

Kirby

This is great news!

I would love to see and try your lg3d.py module. Is it posted anywhere?

Jason -- I've bundled lg3d.py inside of python101.zip, which is linked from each of my 'Numeracy + Computer Literacy' pages e.g. http://www.inetarena.com/~pdx4d/ocn/numeracy0.html -- this zip also contains vrml.py. Both lg3d.py and vrml.py are designed to mimic the interface exported by povray.py, and that's pretty well documented in numeracy1.html -- except that I'm in the process of upgrading povray.py slightly to make it easier to use textures. All of these modules work in complement with coords.py, which contains my general vector classes, e.g. they all give you shaft(v), edge(v1,v2), point(v), and face(vlist), where v,v1,v2 are vectors and vlist is a list of vectors. * shaft(v) draws from the origin to vector tip v, * edge(v1,v2) draws an edge between the tips of v1 and v2, * point(v) draws a sphere at the tip of v, and * face(vlist) makes a polygon going around the points defined by the vectors in vlist (which should all be coplanar). The above methods all belong to whatever output object you've chosen, i.e. some povray or LiveGraphics3D object. So, for example, you could do something like this:

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import povray, coords, lg3d myfile = povray.Povray("coolgraphic.pov") # instantiate povray object v1 = coords.Vector((1,0,0)) # define a vector v2 = coords.Vector((-3,3,0)) # ...and another myfile.edge(v1,v2) # use vectors to make an edge myfile.close() # close the povray file

You would now have a file called "coolgraphic.pov" on your disk ready for rendering in povray, and containing the information for displaying an edge running from (1,0,0) to (-3,3,0). You could have instantiated the Povray object with more parameters (e.g. background color), but just a filename is sufficient. Or, you might have gone:

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myfile = lg3d.Lg3d("coolgraphic.m") v1 = coords.Vector((1,0,0)) v2 = coords.Vector((-3,3,0)) myfile.edge(v1,v2) myfile.close()

...which is essentially the same thing, except you've made myfile an Lg3d object vs. a Povray object -- same methods, but you're creating "coolgraphic.m" on your disk, suitable for embedding as the INPUT_FILE in the applet HTML for LiveGraphics3D. My process for creating the various polyhedra at my website, in LG3D, Povray or VRML formats, is to use the above technology under a Polyhedron or Shape class which pre-assigns all the critical vertex information to vectors, and lists faces as tuples. For example, my Cube class looks like this: class Cube(Shape): """ Labels of Numbers of Shape Volume Vertices Vertices, Edges, Faces --------------------------------------------------------- Duo-tet Cube 3 A-H 8 12 6 """ faces = [('A','H','C','F'),('A','H','B','G'),('B','E','C','H'), ('B','E','D','G'),('D','G','A','F'),('C','E','D','F')] sphcolor = cylcolor = "Green" def __init__(self): Shape.__init__(self) self.volume = 3.0 You can see that 'A' must be the name of some vector, which in this case is actually stored in the module itself as a global variable. That's the entire cube class definition, as all the code for translating, scaling and rotating is in the superclass, i.e. part of Shape's definition (from which Cube inherits). Note: I don't explicitly give the edges, as these are implied in the faces list, i.e. I have code that builds a list of vertex-pairs (edges) from a face-tuple such that ('A','H','C','F') nets me ('A','H'),('H','C'),('C','F'),('F','A') -- just traveling around the perimeter. Of doing all the faces this way nets you each edge twice, so I need to screen for duplications as I build my edges list. The method looks like this: def getedges(self): """Extract edges from the faces list. Face lists contain consecutive vertices, so build and edge list by taking pairs, with the last vertex connecting back to the first. Use sort() to assure each edge is specified uniquely """ edges = [] # locally scoped for face in self.faces: # e.g. ['A','B','C'] for j in range(len(face)): candidate = [face[j],face[j-1]] candidate.sort() # assure uniqueness if not tuple(candidate) in edges: edges.append(tuple(candidate)) # add if new self.edges = edges Anyway, that's the kind of stuff I'm doing on the back end. Kirby

Thank you very much.. wow. so much to explore and so many components coming together :-) Very exciting times we live in.. philosophy, concept, tools, simulation, realization

Thanks Jason. http://groups.yahoo.com/group/math-learn/message/552 is a very recent post to math-learn which introduces some of the same ideas (writing to math teachers, who are mostly chatting about the TI-XX GC -- but there's always hope. This post in turn links to a new web page: http://www.inetarena.com/~pdx4d/ocn/mygraphs.html -- shows source code for doing the LiveGraphics displayed. Now I'm going to check some of these URLs you've been tossing out.

2. How to make lg3d more interactive so now coudl browse & query the datapoints?

I saw from that star system page that you can label the lg3d points. This could be handy. I need to figure out how to add labels. Kirby