> I tested my example of column generation without the routine > lpx_std_basis
> Now, the result is good: > 0: objval = 0.000000000e+00 infeas = 1.000000000e+00 (0) > 15: objval = 3.497400000e+04 infeas = 0.000000000e+00 (0) > * 15: objval = 3.497400000e+04 infeas = 0.000000000e+00 (0) > * 29: objval = 2.652371454e+02 infeas = 0.000000000e+00 (0) > OPTIMAL SOLUTION FOUND > * 29: objval = 2.652371454e+02 infeas = 0.000000000e+00 (0) > * 31: objval = 6.586143114e+01 infeas = 0.000000000e+00 (0) > OPTIMAL SOLUTION FOUND > But, At the 55 st problem, I obtain: > spx_simplex: initial basis is invalid > Why? Normally, the precedent solution is feasible > I don't understand spx_simplex because I don't use. How do I repear > the problem? when the lpx_simplex is different of LPX_E_OK If before changing the problem instance the basis was optimal, you do not need to repair it. Probably you changed the status of some rows/columns, or deleted some active rows and/or basic columns; this invalidates the basis. If you need to delete an active row, just make it free; similarly, to delete a basic column it is sufficient to fix it at zero. _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
