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by joswig
03 Mar 2022, 17:01
Forum: Helpdesk
Topic: Accessing facets and affine hull data structures in C++
Replies: 6
Views: 3994

Re: Accessing facets and affine hull data structures in C++

(1)Is it safe to simply cast the Rational scalar to a double for further usage in my application? In general: no. Rational is an exact type, double is not. If a conversion makes sense or not will depend on what you want to compute. Usually, you just want to stick with Rational. polymake supports ar...
by joswig
03 Mar 2022, 10:08
Forum: Helpdesk
Topic: Accessing facets and affine hull data structures in C++
Replies: 6
Views: 3994

Re: Accessing facets and affine hull data structures in C++

A few more remarks: (1) Specifying polytopes in terms of a V-description works by providing POINTS. Using VERTICES is potentially more efficient, but this requires that the points (i.e., rows of the matrix) are actually, the vertices, and without repetitions. (2) We use a homogeneous coordinate mode...
by joswig
01 Mar 2022, 10:38
Forum: Helpdesk
Topic: Running into a compile error on example C++ code
Replies: 11
Views: 6906

Re: Running into a compile error on example C++ code

In addition to what Ewgenij said, you will need to make sure that the executable polymake-config is in your path.
by joswig
18 Feb 2022, 15:48
Forum: Helpdesk
Topic: Betti numbers wrong for a patchworked curve ?
Replies: 3
Views: 2939

Re: Betti numbers wrong for a patchworked curve ?

You were right: the documentation in polymake was lacking. I added a short comment with a reference to our paper. This will appear in the next release.

So, thank you for helping to make polymake better.
by joswig
18 Feb 2022, 12:07
Forum: Helpdesk
Topic: Betti numbers wrong for a patchworked curve ?
Replies: 3
Views: 2939

Re: Betti numbers wrong for a patchworked curve ?

Our implementation is slightly more general than primitive patchworking; it covers what is sometimes is called "combinatorial patchworking" in the literature. This means, we require that the lattice points (@my_monomials in your case) correspond to the entire set of monomials in, say, n va...
by joswig
27 Jan 2022, 20:30
Forum: Helpdesk
Topic: Visualization bug(?) in Polymake 4.6
Replies: 3
Views: 9314

Re: Visualization bug(?) in Polymake 4.6

We did make changes concerning threejs in order to obtain correct visualization for https://www.matchthenet.de/xmas. And I can confirm your problem.

Requires an investigation. Stay tuned.
by joswig
12 Jan 2022, 12:04
Forum: General Discussion
Topic: Convex Decomposition
Replies: 5
Views: 13751

Re: Convex Decomposition

That does not have unique solutions. Instead the set of such solutions forms a polyhedron in the parameter space (= coefficients of the linear combinations).
by joswig
12 Jan 2022, 09:30
Forum: General Discussion
Topic: Convex Decomposition
Replies: 5
Views: 13751

Re: Convex Decomposition

Sorry, I don't understand the question.

Is it that P_2 is a subpolytope of P_1, and you want to find those vcertices of P_1 which are not vertices of P_2?
by joswig
25 Oct 2021, 17:44
Forum: Helpdesk
Topic: Saving Polytope Vertices to CSV or TXT
Replies: 1
Views: 2363

Re: Saving Polytope Vertices to CSV or TXT

Your command sequence > $p = cube(3); > print($p->VERTICES); > save_data($p->VERTICES, "my_vertices.txt"); is perfectly OK; the result is a JSON file (format defined by polymake) which contains just one matrix plus a bit of metadata. If you want the matrix (coefficients separated by blanks...
by joswig
28 Sep 2021, 10:23
Forum: General Discussion
Topic: how to define integer polytope by matrix representation
Replies: 6
Views: 15099

Re: how to define integer polytope by matrix representation

Your example has a lineality space of positive dimension. polytope > $p = new Polytope(INEQUALITIES=>[[13,-6,0,-7,0,-9,0],[11,0,-8,0,-5,0,-6]],EQUATIONS=>[[-1,1,1,0,0,0,0],[-1,0,0,1,1,0,0],[-1,0,0,0,0,1,1]]); polytope > print $p->VERTICES; 1 -1/4 5/4 1 0 5/6 1/6 0 1 -1 0 0 -2/3 2/3 0 1 -1 0 0 -4/3 4...

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