Andrew, >> Another thing that I noticed (but is probably normal behaviour) is >> that --proxy takes some time to find a solution when compiled with >> optimisations and x87 floating point, where using only --bestp a first >> solution is found quickly with both sse and x87 floating point. > > To find a first integer feasible solution it is better to use --bestp > rather than --bestb (the latter is default option). The best projection > heuristic (--bestp) selects a subproblem whose solution to lp relaxation > is close to an integral point while the best bound heuristic (--bestb) > attempts to minimize the size of the search tree.
What I was trying to say is that the first stage of proximity search (as implemented) is using the solver with best projection search to find an initial solution, so I was (naively) expecting similar performance when using --bestp on the command line. However the proximity search one takes an order of magnitude more iterations for the first solution. I understand that the search is probably just taking a different path, but maybe it offers a hint. Best Regards Chris Matrakidis _______________________________________________ Help-glpk mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-glpk
