> I am trying to solve a network flow problem which has some integer > constraints as well. Anyway, I've formulated the problem in CPLEX > form, and glpsol then solves it, but it takes close to 10 minutes to > do so. But when I use the API directly, calling lpx_read_cpxlp > followed by calls to lpx_simplex and lpx_integer, I get the same > optimal solution in less than a minute. Is there any reason why glpsol > is so much slower (by almost an entire order of magnitude!) than > direct calls to the API? I've tried looking through the archives but > couldn't find any discussion on this. Any help on this would be > appreciated. Many thanks in advance.
This is normal in integer optimization. By default glpsol performs scaling and starts lp optimization from an advanced basis; this may lead to an optimal basis of lp relaxation which differs from the one you obtained using api. You can disable scaling and crashing as follows: glpsol --noscale --std ... _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
