[PPL-devel] Opposing inequality to equality conversion.
Axel.Simon at ens.fr
Fri Feb 6 10:56:57 CET 2009
I'm trying to verify a claim in Halbwachs' paper on factoring
polyhedra ("Some ways to reduce the space dimension in polyhedra
computations" is the journal version). Specifically, he claims that
omitting a common equality relation from the convex hull computation
yields not significant speedup. I've tried to run a convex hull
calculation, once with the common equalities added and once with the
common equalities omitted and found quite a difference in
performance. However, I added the equality as two opposing
inequalities. My question: are the two opposing inequalities not
immediately turned into one equality by the Constraint class? If not,
then this might explain the speed difference I'm seeing.
Any help appreciated,
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