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Regular subdivisons of point configurations

Posted: 12 Nov 2012, 11:58
by aurelien
I would like to compute the regular subdivision of a polytope. I've been trying to follow the tutorial here

http://www.polymake.org/doku.php/tutori ... bdivisions

but the instructions seem to be for an older version of polymake. I am using version 2.12.

How is the regular subdivision of a polytope computed in version 2.12?

Thank you

Re: Regular subdivisons of point configurations

Posted: 12 Nov 2012, 18:19
by joswig
Please use the function regular_subdivision:

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polytope > help "regular_subdivision"; functions/Subdivisions/regular_subdivision: regular_subdivision(points, weights) -> Array<Set<Int>> Compute a regular subdivision of the polytope obtained by lifting points to weights and taking the lower complex of the resulting polytope. If the weight is generic the output is a triangulation. Arguments: Matrix points Vector weights Returns Array<Set<Int>>
To produce a suitable "big" object, you can do, for instance:

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polytope > $Pts=cube(2)->VERTICES; polytope > $C=new fan::PolyhedralComplex(POINTS=>$Pts,MAXIMAL_CELLS=>regular_subdivision($Pts,new Vector([0,0,0,1])));
Then you can try like

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polytope > print $C->MAXIMAL_CELLS; {1 2 3} {0 1 2} polytope > $C->VISUAL;

Re: Regular subdivisons of point configurations

Posted: 13 Nov 2012, 13:51
by aurelien
Great, thanks for the quick response.