I think this instance of the model is quite hard to solve. I run glpsol for more than 1 hour and it did not find an initial solution. Only fpump found a solution at pass 9 but I aborted it. I am running it again.
I also run cbc-solver for 1 hour and 2 hours with same model. No solution as well. Noli On 4/6/16, Andrew Makhorin <[email protected]> wrote: >> OK. It is feature but it seems not a good feature. > >> I tried to modify the npass (default 5) to npass <=10 and fpump finds >> a solution in npass 9 and it starts again from pass 1 to pass 10. It >> takes a long time to finish the job. >> > > Well, all primal heuristic work in this way--usually it is reasonable to > spent some time to find a good initial solution rather than to spent a > lot of time to close a large integrality gap during the b&b search. The > only question is when to stop. May be to add a time limit like for PROXY > heuristic. On the other hand, if your instance is not hard, i.e. if the > b&b solver finds an initial solution quickly, using primal heuristic(s) > is not needed. > > > _______________________________________________ Bug-glpk mailing list [email protected] https://lists.gnu.org/mailman/listinfo/bug-glpk
