> 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
