Using Polyhedron as you are doing is the correct way to compute convex hulls in Sage. If your vertices are integral, then you could also try using the LatticePolytope class. LatticePolytope uses PALP instead of cddlib, and so might be faster for some inputs.
I have meant for a long time to make lrs an optional backend for computing convex hulls, but I have never found the time. For some inputs lrs is much faster than cddlib, but it is difficult to tell in advance which will be better. I did make an optional lrs package for Sage, and thanks to the work of others (Volker Braun primarily) the Polyhedron class could be extended to use lrs pretty easily. In the past when I looked at qhull it seemed poorly supported and could not do exact computations in high dimensions. I just looked at the project page and it has been updated recently so maybe it would be good to revisit it. A first step would be making an optional spkg of qhull for Sage. For years the Sage interface to polymake has been broken, and it was never very complete. Polymake also uses cddlib and lrs, so there would be no advantage there, but it also has a beneath-and-beyond implementation that is sometimes faster than cddlib or lrs. So you might want to see if that works for you. I've always had a lot of trouble compiling polymake, and for various reasons its doubtful it could be made a standard component of Sage, so I have preferred to work on Sage-native solutions. But it would be great to have a working interface to it in Sage. Hope that helps. Marshall Hampton On Jul 17, 4:24 pm, tvn <[email protected]> wrote: > I use p = Polyhedron(vertices=set_of_vertices) to compute the convex > hull of the given set_of_vertices. It works fine except way too slow > when dealing with high dimension and large set of vertices. I am > wondering if there's anyway to speed up the process. > > 1) Is using Polyhedron() the correct way to compute convex hull in > Sage ? is there another way ? > > 2) There's another program/algorithm called qhull that works very > fast --- anyone has considered implementing that algorithm in > Sage ? -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
