>> At the second simplex, GLPK starts with an objval=0 instead of the >> precedent solution. > >> Why? > > If you add columns to the problem object, they become non-basic, > so the optimal basis must remain at least primal feasible, however, > it is primal infeasible (as seen from the solver output). Which > changes in the problem object did you make before re-optimiziation? > Looks like you changed bounds of some basic rows/columns.
Make sure that after addition of new columns to the problem object they are non-basic and on their *zero* bounds. If a new column has a non-zero bound, adding it (along with the column of the constraint matrix) may make the basis primal infeasible. _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
