MAKE A MEME
View Large Image
| View Original: | Double six.svg (635x612) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: Double six.svg Schläfli's double six configuration ” twelve lines with five intersection points per line and two lines per intersection point intersecting in the pattern of a crown graph ” inscribed on a cube following an illustration by Hilbert and Cohn-Vossen in Geometry and the Imagination own David Eppstein 2010-07-31 Source code The basic geometry of this image was created with the following Python script much of which was copied from the one used for File Gray configuration svg The transparency effects were added afterwards using Adobe Illustrator <source lang python > from pyx import canvas path color from math import sqrt tan asin pov -22 7 7 1 9 3 x y z 2 1 0 radius 0 12 scale 10 0 g 2 0 h 2 5 vertexColor color rgb red edgeColor color rgb black cubeColor color rgb blue def distance p q return sqrt sum pi-qi 2 for i in x y z def perspective loc dz locz-povz return locx-povx scale/dz locy-povy scale/dz def vertex p lx ly perspective p prad scale 1 1 tan asin radius/ distance p pov c fill path circle lx ly prad vertexColor def edge p q lx1 ly1 perspective p lx2 ly2 perspective q c stroke path line lx1 ly1 lx2 ly2 edgeColor def cube p q lx1 ly1 perspective p lx2 ly2 perspective q c stroke path line lx1 ly1 lx2 ly2 cubeColor c canvas canvas def transform point spin flip mirror turn x y z point if mirror x y z y x z if turn x y z -x -y z if flip x y z -y x -z for i in range spin x y z y z x return x y z points set lines set for s in 0 1 2 for f in 0 1 points add transform 0 0 g s f 0 0 for m in 0 1 for t in 0 1 points add transform g g/h g s f m t points add transform g h g g s f m t lines add transform g h g g s f m 0 transform -g h -g g s f m 0 for a in -2 2 for b in -2 2 cube a b -2 a b 2 cube a -2 b a 2 b cube -2 a b 2 a b for p q in lines edge p q for p in points vertex p c writePDFfile Double_six </source> Projective geometry Files by User David Eppstein from en wikipedia Crown graph 6 | ||||
