Hello Xiaomi, if the basic solution is not primal/dual feasible within a tolerance the warning you observed is written.
The tolerances are passed in structure glp_smcp to the simplex solver as fields tol_bnd and tol_dj, both defaulting to 1e-7. This may be caused by bad scaling of the model, e.g. excessive values of M in a big M approach. see http://lists.gnu.org/archive/html/help-glpk/2003-10/msg00004.html http://en.wikibooks.org/w/index.php?title=GLPK/Terminal_output#Numerical_instability Best regards Xypron -------- Original-Nachricht -------- > Datum: Thu, 7 Oct 2010 13:48:56 -0400 > Betreff: [Help-glpk] what does it mean by "Numerically instability" > When I solve the LP file in GLPK 4.44, there are multiple same warnings: > > Numerically instability (primal simplex, phase I) > > What does that mean? Thanks. > > _______________________________________________ > Help-glpk mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/help-glpk -- Neu: GMX De-Mail - Einfach wie E-Mail, sicher wie ein Brief! Jetzt De-Mail-Adresse reservieren: http://portal.gmx.net/de/go/demail _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
