forum.polymake.org

Posted: **23 May 2013, 16:21**

Hi. This forum is great.

I'm having a problem visualizing a zonotope with jReality, which I define as follows:

polytope > $zm= new Matrix<Rational>([[0,1,-1,0,0,1,0,-1,0],[0,1,-1,0,0,0,1,0,-1],[0,0,0,1,-1,1,0,-1,0],[0,0,0,1,-1,0,1,0,-1]])
polytope > $zv=zonotope($zm)

polytope > print $zv;
1 2 -2 2 -2 2 2 -2 -2
1 0 0 2 -2 0 2 0 -2
1 0 0 2 -2 2 0 -2 0
1 -2 2 2 -2 0 0 0 0
1 2 -2 0 0 0 2 0 -2
1 0 0 0 0 -2 2 2 -2
1 0 0 0 0 0 0 0 0
1 -2 2 0 0 -2 0 2 0
1 2 -2 0 0 2 0 -2 0
1 0 0 0 0 0 0 0 0
1 0 0 0 0 2 -2 -2 2
1 -2 2 0 0 0 -2 0 2
1 2 -2 -2 2 0 0 0 0
1 0 0 -2 2 -2 0 2 0
1 0 0 -2 2 0 -2 0 2
1 -2 2 -2 2 -2 -2 2 2

polytope > print $z->VERTICES;
polymake: used package cddlib
  Implementation of the double description method of Motzkin et al.
  Copyright by Komei Fukuda.
  http://www.ifor.math.ethz.ch/~fukuda/cdd_home/cdd.html

1 2 -2 2 -2 2 2 -2 -2
1 0 0 2 -2 0 2 0 -2
1 0 0 2 -2 2 0 -2 0
1 -2 2 2 -2 0 0 0 0
1 2 -2 0 0 0 2 0 -2
1 0 0 0 0 -2 2 2 -2
1 -2 2 0 0 -2 0 2 0
1 2 -2 0 0 2 0 -2 0
1 0 0 0 0 2 -2 -2 2
1 -2 2 0 0 0 -2 0 2
1 2 -2 -2 2 0 0 0 0
1 0 0 -2 2 -2 0 2 0
1 0 0 -2 2 0 -2 0 2
1 -2 2 -2 2 -2 -2 2 2

This gives a 3-d polytope and every seems to work fine, but when i do $z->VISUAL; it responds

Code: Select all

polymake:  ERROR: could not provide all required input properties at input line 1.

Am I doing something wrong? (I tested VISUAL with the usual examples and it worked properly). Thanks in advance!!

Posted: **23 May 2013, 17:28**

You can only visualize polytopes with AMBIENT_DIM <= 3 (or 4, if you like Schlegel diagrams). The AMBIENT_DIM of your polytope is

Code: Select all

polytope > print $zv->AMBIENT_DIM;
8

You could project your 3-dim polytope to 3-space via

Code: Select all

polytope > $zv_proj = projection_full($zv);
polytope > print $zv_proj->AMBIENT_DIM;
3

However, you should be careful with the interpretation of the visualized polytope $zv_proj. Different projection maps may lead to different (unexpected) images.

forum.polymake.org

Problem with zonotope visualization

Problem with zonotope visualization

Re: Problem with zonotope visualization