August 2002 - PPL-devel - BUGSENG Mailman

Question regarding speed of the library
by Martin Rohde 01 Sep '02

01 Sep '02

Hello, I have a question regarding the speed of the PPL0.4.1 library. I'm using the library now for calculating the intersection of two convex polyhedra. During my calculations, a large number of intersections must be calculated (say 50000 times). The library does its calculations very well, but it costs a lot of time to calculate an intersection. In my code I do the following: 1. Add generators to a polyhedron 1 2. Add generators to a polyhedron 2 3. Calculate the intersection of polyhedra 1 and 2 4. Store the constraints and the generators in an array (I convert all coefficients to doubles) This process costs 100 seconds for 30000 calculations (so 30 intersections per second) on a 600MHz machine. When I remove step 3 (so I skip the intersection), the calculation takes about the same amount of time. So, the intersection is not the time consuming step. But removing step 1 and/or 2 speeds up the calculation significantly! So I might conclude that the ph.add_generator(ax+by+cz) is very slow. My questions are now: - is add_generator slow indeed? - How can I speed up the code? Thank you for your help! Martin Rohde

2 1

Question PPL : abort?
by Martin Rohde 01 Sep '02

01 Sep '02

Hello, I have a second question, which relates to my previous mail message. After calculating, say, 25000 intersections of polyhedra, I get an 'abort' error message. It terminates the program. What does this mean? Martin Rohde

2 1

ppl/interfaces/Prolog Prolog_interface.dox pl_ ...
by Patricia Hill 22 Aug '02

22 Aug '02

CVSROOT: /cvs/ppl Module name: ppl Changes by: hill(a)cs.unipr.it 2002-08-22 15:41:50 Modified files: interfaces/Prolog: Prolog_interface.dox pl_check.pl Log message: Updated for concatenate_assign. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/interfaces/Prolog/Prolog_inte… http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/interfaces/Prolog/pl_check.pl…

1 0

ppl/src PowerSet.inlines.hh
by Roberto Bagnara 22 Aug '02

22 Aug '02

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2002-08-22 10:45:44 Modified files: src : PowerSet.inlines.hh Log message: PowerSet<CS>::add_constraint() and PowerSet<CS>::add_constraints() fixed. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/PowerSet.inlines.hh.diff?…

1 0

ppl/tests hypercubes.cc
by Enea Zaffanella 22 Aug '02

22 Aug '02

CVSROOT: /cvs/ppl Module name: ppl Branch: alt_nnc Changes by: zaffanella(a)cs.unipr.it 2002-08-22 01:10:40 Modified files: tests : hypercubes.cc Log message: Some more tests. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/tests/hypercubes.cc.diff?cvsr…

1 0

ppl/src PowerSet.inlines.hh
by Roberto Bagnara 20 Aug '02

20 Aug '02

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2002-08-20 17:21:07 Modified files: src : PowerSet.inlines.hh Log message: Several corrections. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/PowerSet.inlines.hh.diff?…

1 0

ppl/src Polyhedron.defs.hh
by Roberto Bagnara 19 Aug '02

19 Aug '02

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2002-08-19 22:38:43 Modified files: src : Polyhedron.defs.hh Log message: Avoid unnecessary qualification. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Polyhedron.defs.hh.diff?c…

1 0

ppl/src ConSys.cc ConSys.defs.hh GenSys.cc Gen ...
by Roberto Bagnara 19 Aug '02

19 Aug '02

1 0

ppl/src Status.defs.hh Status.cc Polyhedron.cc
by Roberto Bagnara 19 Aug '02

19 Aug '02

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2002-08-19 16:56:57 Modified files: src : Status.defs.hh Status.cc Polyhedron.cc Log message: The input and output operators on Status have been replaced by methods void ASCII_dump(std::ostream&) const and bool ASCII_load(std::istream&). Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Status.defs.hh.diff?cvsro… http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Status.cc.diff?cvsroot=pp… http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Polyhedron.cc.diff?cvsroo…

1 0

ppl/src Polyhedron.defs.hh
by Roberto Bagnara 19 Aug '02

19 Aug '02

CVSROOT: /cvs/ppl Module name: ppl Changes by: roberto(a)cs.unipr.it 2002-08-19 16:55:10 Modified files: src : Polyhedron.defs.hh Log message: Comment corrected. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/src/Polyhedron.defs.hh.diff?c…

1 0