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by herr
21 Nov 2013, 16:38
Forum: Helpdesk
Topic: Computing the dual of a polytope
Replies: 6
Views: 6326

Re: Computing the dual of a polytope

Dear Phillip, thanks for the nice description of your example. You've chosen the correct function polarize() for the task, and the result is consistent with the definition of the polarized polytope used in polymake. A polytope P in polymake is of the form P = {x|b + Ax >= 0} The polarized polytope (...
by herr
15 Jul 2013, 22:59
Forum: Helpdesk
Topic: Constructing Uniform Polytopes
Replies: 5
Views: 6692

Re: Constructing Uniform Polytopes

herr, it seems that the information in TRANSVERSAL_SIZES does reflect the polytope, however. For example, the 3-cube, cuboctahedron, and octahedron, which all have the same symmetry group, have transversal sizes (8,3,2), (12,2,2), and (6,4,2), respectively. For regular polytopes, it seems to give t...
by herr
15 Jul 2013, 18:27
Forum: Helpdesk
Topic: Constructing Uniform Polytopes
Replies: 5
Views: 6692

Re: Constructing Uniform Polytopes

One thing I'm looking at is whether the symmetry group is transitive on the faces of each dimension. The properties TRANSVERSALS and TRANSVERSAL_SIZES of GroupOfPolytope seem interesting for this, but I don't understand what they mean. Can someone explain them? Unfortunately, the properties TRANSVE...
by herr
25 Jun 2013, 13:49
Forum: Helpdesk
Topic: Could Polymake solve a 20-dimension problem?
Replies: 2
Views: 4024

Re: Could Polymake solve a 20-dimension problem?

It is hard to predict whether polymake (or any convex hull code) is able to cope with a polytope in dimension 20 given by such a lot of points. The resulting number of facets could be incredibly large, see also the discussion in this post . It really depends very much on the specific properties of y...
by herr
25 Jun 2013, 13:33
Forum: Helpdesk
Topic: Strange result using VISUAL
Replies: 1
Views: 2266

Re: Strange result using VISUAL

Hi Borgo,

This is a bug, I'm afraid. As a workaround, I suggest to use the tools provided by the jReality-GUI: Click the option "Polymake->Clear Attribute", then open the panel "Left Slot" via "Window->Left Slot" and change the colors manually.
by herr
23 May 2013, 17:28
Forum: Helpdesk
Topic: Problem with zonotope visualization
Replies: 1
Views: 2433

Re: Problem with zonotope visualization

You can only visualize polytopes with AMBIENT_DIM <= 3 (or 4, if you like Schlegel diagrams). The AMBIENT_DIM of your polytope is polytope > print $zv->AMBIENT_DIM; 8 You could project your 3-dim polytope to 3-space via polytope > $zv_proj = projection_full($zv); polytope > print $zv_proj->AMBIENT_D...
by herr
26 Feb 2013, 11:47
Forum: Helpdesk
Topic: How to add inequalities to a polyhedron
Replies: 1
Views: 2378

Re: Documentation / tutorial for beginners?

Dear Attila, You cannot add inequalities to an existing polytope, this is simply not the right way to look at a polymake object. Once you created an object, the properties (like INEQUALITES) you specified become immutable. This is necessary because polymake computes other properties from the given p...
by herr
15 Feb 2013, 15:58
Forum: Helpdesk
Topic: Visualization problems
Replies: 3
Views: 3026

Re: Visualization problems

Hi, It's not a visualization issue. The problem is that you didn't really construct the 3-simplex, but some 2D-polyhedron with several rays. Compare your input with print simplex(3)->VERTICES; The reason is that polymake uses homogeneous coordinates (see the Tutorial on Coordinates ). Practically, i...
by herr
21 Jan 2013, 20:28
Forum: Helpdesk
Topic: Constructing a polytope from a list of facets
Replies: 2
Views: 2810

Re: Constructing a polytope from a list of facets

Hi Nicolas, The problem is that your polytope $p is not fulldimensional: polytope > print $p->DIM; 2 Since your polytope is 2-dimensional in R^4, its affine hull is nontrivial: polytope > print $p->AFFINE_HULL; -1 0 1 1 0 -1 1 0 0 1 Therefore, the representation of a facet is not unique. The polytop...
by herr
14 Sep 2012, 08:55
Forum: Helpdesk
Topic: Testing for affine mapping between two polytopes
Replies: 1
Views: 2164

Re: Testing for affine mapping between two polytopes

Unfortunately, there is no such method available in polymake. It is possible to compute the linear symmetries of a polytope via the user function linear_symmetries which wraps functionality of sympol. Using sympol directly, you could compute the linear symmetries of both polytopes and compare the re...

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