>> Lpx_warm_up computes the basis factorization only if it does not exist, >> i.e. if glp_bf_exists returns zero.
> Does changing the status of a basic variable to > nonbasic cause glp_bf_exists to return nonzero? Yes. Any changes in the problem object that change the current basis matrix invalidate the factorization. For example, changing the status of a basic variable to a non-basic and vice versa, changing the basic column of the constraint matrix, changing the row of the constraint matrix which changes at least one basic column, etc. >> Yes, there must be added an api routine to update the factorization >> on changing the basis when a specified basic variable leaves the basis >> and a non-basic one enters it. > For what I have in mind, I need to specify > both the entering and leaving variables. I meant an api routine similar to CPXpivot (used in cplex). Such routine exists (it is used internally by the simplex method routines), however, it is not available on api level. _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
