[PPL-devel] Question about looping through lattice vertices inside a bounded convex polyhedron

[Enea Zaffanella]

On 06/25/2012 08:22 PM, SADOVSKY, ALEXANDER V. (ARC-AFH) wrote:
> Hello,
>
> I have a bounded convex polytope, defined by a collection of linear
inequalities. What I need is to be able to loop programmatically through
all points that have integer coordinates and are contained in the
polytope. There are some occurrences of the string "loop" in the
documentation, but I couldn't understand what "loops" are meant there,
nor how to write, say, a FOR- or WHILE-loop that will list all the
points in the finite set I described above.
>
> Any help would be greatly appreciated. >
> Thanks,
> Alex Sadovsky
> NASA Ames Research Center
> AFH, Mail stop 210-6
> Moffett Field, CA 94035
> 650 604 2331 (ph)
> 650 604 0174 (f)
> _______________________________________________
> PPL-devel mailing list
> PPL-devel at cs.unipr.it
> http://www.cs.unipr.it/mailman/listinfo/ppl-devel
>


Hello Alex.

The PPL does not provide the service you are asking for.

Using the domain of convex rational polyhedra, you can obtain the list 
of _extreme_ _rational_ points of your polytope: besides possibly having 
non-integer coordinates, these won't include points that are not 
vertices of the polytope.

Depending on your needs, you can however try some quick (possibly 
inefficient) workaround. See, for instance, the following thread:

http://www.cs.unipr.it/pipermail/ppl-devel/2012-March/018096.html

Hope this helps.

Enea.