> Beware: > 1.999999999999999 and 2.000000000001 likely won't lie in the same > bin. You'll need to check neighbors for candidates, unless your fixed > point stuff reflects an underlying granularity. > > -- Scott David Daniels > [EMAIL PROTECTED]
Thanks for the heads up Scott. I'm translating a volume 3 cube around in a 3D checkerboard, trying to flag all kitty-corner mid-edges (my bridge points), but not flagging border-line edges where the connector tabs shouldn't appear -- some large borg-like array of icosahedra connected by zig-zag tensed bands (Lanahan's patent pending). See http://www.4dsolutions.net/satacad/pythonicmath/icosa_in_holder.jpg for a picture of a unit cell (the array might contain thousands). So the XYZ tuples of interest are indeed highly distinct and in a regular grid pattern. It's just that there're a whole lot of them, and if I could find a hash key that'd keep only the unique ones unique and ignore floating point fuzz, I'd be set. Any pairing/doubling would define a bridge point, and therefore a green light to render a tab connector. I think the key is probably to transform the grid by scaling, such that my mid-edge points of interest get expressed using all integer coordinates. Even though my actual map is floating point, the isomorphism will work for pruning, and the tuples'll be easy to manage (so maybe scratch the decimal type idea for now). I'll post again when I have more research behind me and either a solution or concrete frustration in sight -- not before. Kirby _______________________________________________ Edu-sig mailing list Edu-sig@python.org http://mail.python.org/mailman/listinfo/edu-sig