Linearly increasing the lift values does not work. I can find a relatively small example (81 vertices in 4 dimensions) where your patch fails.
For higher dimensions I think using lrs is really the way to go, since adding it has other advantages as well. When I have a little time I will try to write an interface to use it for triangulation. I am putting the other improvements from your patch into another merged patch. Can you review it? Cheers, Marshall > On Oct 4, 7:59 pm, "Arnaud Bergeron" <[EMAIL PROTECTED]> wrote: > > > 2008/9/29 mhampton <[EMAIL PROTECTED]>: > > > > I thought I would explicitly point this one out because I had been > > > reviewing #4164 (work by Arnaud Bergeron), but now I am also > > > contributing code and I think the best scenario is to have someone > > > else take a look. Mike Hansen has looked at polyhedra.py before, so > > > he is a candidate if willing, but it would be great if someone else > > > takes a look. Polyhedra.py (in sage/geometry) is still in its early > > > stages; eventually I hope for it and other things in the geometry > > > group to provide most of the functionality of polymake and other > > > packages if they can't be made part of standard sage. Because the > > > optimal design is far from clear to me, I want to encourage more > > > eyeballs on it (I am an enthusiastic amateur when it comes to > > > polytopes, not an expert). > > > > Marshall Hampton > > > About this patch I have an idea for an improvement that would make it > > work 100% in all cases. I can't believe I didn't think of this > > sooner. > > > The idea is that instead of adding a random value in the extra > > dimension for the lifting we can only add an monotonically increasing > > value. I tried this on the simple 4D example that was in doctest > > before as well as the monster that crashed my code (and my hopes) > > before and they both worked repeatedly (with a newly created > > polyhedron, otherwise it just hits the cache). > > > I visualized the monster one (with ugly hacks) and the results looks > > correct. I haven't manually inspected every surface produced though, > > so there might be some errors. > > > So I turn to you (or anybody else that wants) for examples that could > > break this before submitting final version no 42 to trac. > > > Use the attached patch (requires trac_4164_merge.patch from the trac > > ticket) to try yourself or send me lists of vertices for polyhedron. > > > Arnaud > > > tentative_4164.patch > > 1KViewDownload --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
