> I am trying to solve a large binary problem of linear programming, > with 38640 columns and 2116 rows.
> GLPK finds an optimal solution, but the integer optimization > doesn't. Probably your instance is hard for the glpk b&b solver. > After a long computation (with some warning as: "spx_simplex: > numerical instability (dual simplex)"), the program exits in such a > way: > spx_invert: the basis matrix is singular > spx_simplex: numerical problems with basis matrix > spx_simplex: sorry, basis recovery procedure not implemented yet > mip_driver: cannot solve current LP relaxation > + 16108: mip = not found yet >= 5.071593581e+06 (42; 0) > lpx_integer: cannot solve current LP relaxation > Someone can help me? If you wish, you can write your model in mps format, gzip it, and post it to me <[EMAIL PROTECTED]> (up to 10 Mb is ok; please do not post it to the list). It is difficult to say something reasonable not seeing the model. Andrew Makhorin _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
