Ticket #4676 (new enhancement)

Opened 1 month ago

Last modified 1 week ago

[with patch, positive review pending changes] Polyhedral improvements

Reported by: mhampton Assigned to: mhampton
Priority: minor Milestone: sage-3.4
Component: geometry Keywords: polyhedra, polytopes
Cc: abergeron

Description

This adds more built-in polytopes (more Archimedean solids) and some new methods such as the Gale transform, bipyramid construction, edge truncation, and perspective projection with (optionally) hidden faces invisible. The Schlegel projection code has also been somewhat refactored to make it more general in the future.

Attachments

4676_polyhedra_1.patch (15.5 kB) - added by mhampton on 12/02/2008 09:18:27 AM.
based against 3.2.1-rc1

Change History

12/02/2008 09:18:27 AM changed by mhampton

  • attachment 4676_polyhedra_1.patch added.

based against 3.2.1-rc1

12/02/2008 09:18:58 AM changed by mhampton

  • summary changed from Polyhedral improvements to [with patch, needs review] Polyhedral improvements.

12/05/2008 01:46:18 AM changed by mabshoff

  • cc set to abergeron.

Arnaud,

can you review this?

Cheers,

Michael

12/24/2008 08:46:26 AM changed by jason

I applied this to 3.2.2 successfully. No doctests were broken in the affected file (there was one doctest that returned an error both before and after the patch, but the warning points to an error in my install, not in the code). I generated lots of pretty pictures, one for each of the new polytopes. Everything seemed to work. However, it would probably be good to have someone who is more familiar with the math look at this.

12/25/2008 08:01:23 AM changed by wdj

I like this too. I checked the Gale transform against section 5.3 in Ewald, Combinatorial convexity and algebraic geometry, and it agreed with the example there.

I wish there was a way to use tachyon to plot the objects but the viewer='tachyon' option is ignored. I agree with Jason that the plots are beautiful anyway.

I give this a thumbs up but maybe Arnaud should review this too? Based on a recent "code freeze" email from Michael Abshoff, it seems as though it will not make 3.3.

12/30/2008 12:54:46 PM changed by abergeron

  • summary changed from [with patch, needs review] Polyhedral improvements to [with patch, positive review pending changes] Polyhedral improvements.

Only two small stylistic points:

- Gale_transform() -> gale_transform() - Schlegel_transform() -> schlegel_transform()

I don't think it's good style to have methods begin with a capital, even when they refer to a person's name.

Otherwise, I don't know since when I was familiar with the math involved. I did look up references though, and everything looks good.

If the two points above are fixed, then I give it a positive review.