## Computing the coordinates of the Vertices_in_facets ?

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Lai
Posts: 7
Joined: 02 Jul 2019, 02:26

### Computing the coordinates of the Vertices_in_facets ?

Hello,

I am quite new to both polymake and programming and my question is this:

I have a 6 dimensional polytope with 48 vertices, and I am interested in computing the vertices that are contained in each facet. I was able to use the VERTICES_IN_FACETS command which is great, however I would love to have the vertices in terms of their coordinates instead of indexed by an integer label.

Is it possible to do this with a polymake command?

Thank you very much!

gawrilow
Main Author
Posts: 386
Joined: 25 Dec 2010, 17:40

### Re: Computing the coordinates of the Vertices_in_facets ?

Numbers in VERTICES_IN_FACETS refer to the rows of VERTICES matrix.
You can do something like this:

Code: Select all

# $p is the Polytope object for my$i (0 .. $p->N_FACETS-1) { print "facet$i contains vertices:\n", $p->VERTICES->minor($p->VERTICES_IN_FACETS->row(\$i), All), "\n"; } 

Lai
Posts: 7
Joined: 02 Jul 2019, 02:26

### Re: Computing the coordinates of the Vertices_in_facets ?

Thank you very much, it worked wonderfully.