> memory problem solving a 4221 var and 1336 constraints > I have a > memory problem solving a simplex (real variables) with 4221 var and > 1336 inequality constraints > The file written by glpk routine glp_write_lp() amounts to 140 MBytes. > When I read this file and try to solve it, memory usage climbs up to > 1.5 Gbytes. > Then the malloc death sentence falls "umalloc: size = 8016; malloc > failed ".
> Why does my problem need so much RAM within glpk ? > I would expect far less. > When glpk reads the file, it says it has 1336 rows (correct), > 8 910 531 columns (why?) > and 1 312 263 non zero values in the matrix. Hmm... There is something wrong. How do you build your instance before writing it with glp_write_lp? Are you using glpk api? Why do you think it has 4221 columns, not 8 910 531 ones? > Any help ? > Is it possible to handle glpk so that it minimises memory usage ? > Or should I think about another solver (which I don't want to!) _______________________________________________ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
