Xypron, Is there a way to access the shadow prices (dual values) for the non-integer variables in a MIP problem?
Adam Greenhall University of Washington xypron wrote: > > Hello Wafa, > > unfortunately the current release does not support accessing dual values > in glpsol in the post processing phase. > > I have suggested to patch GLPK to allow this. > > You can download the patched source using subversion: > svn co svn://glpk.dyndns.org/svn/glpk/glpk/branches/glpk-4.35-dot/ > > For variables you can access lower bound (lb), upper bound (ub), dual > value (dual), value (val) of a variable x[3] like this: > x[3].dual > x[3].lb > x[3].ub > x[3].val > > For constraints you can access lower bound (lb), upper bound (ub), dual > value (dual) of a constraint C[3] like this: > c[3].dual > c[3].lb > c[3].ub > > Best regards > > Xypron > > > > Wafa.Rezig wrote: >> >> >> Hello, >> >> I am using "result" command >> to access the decision variables in GLPK, but dont know how to access the >> shadow prices (marginal price)? >> Is there any documentation about all >> commands. >> Thanks >> >> Wafa Rezig >> OR Analyst >> AISystems, Belgium >> Phone: +32-2-558-88-23 >> Mobile: +32-478-54-39-57 >> >> Legal disclaimer >> >> This electronic message contains information that is confidential. The >> information is intended to be for the use of the addressee only. >> If you are not the addressee we appreciate your notification in this >> respect >> and please note that any disclosure, copy, distribution or use of the >> contents >> of this message is prohibited and may be unlawful. We have taken every >> reasonable precaution to ensure that any kind of attachment to this >> e-mail >> has been swept for viruses. However, we cannot accept liability for any >> damage sustained as a result of software viruses and would advise that >> you carry out your own virus checks before opening any attachment. >> >> Hello, >> >> I am using "result" command >> to access the decision variables in GLPK, but dont know how to access the >> shadow prices (marginal price)? >> Is there any documentation about all >> commands. >> Thanks >> >> Wafa Rezig >> OR Analyst >> AISystems, Belgium >> Phone: +32-2-558-88-23 >> Mobile: +32-478-54-39-57 >> >> Legal disclaimer >> >> This electronic message contains information that is confidential. The >> information is intended to be for the use of the addressee only. >> If you are not the addressee we appreciate your notification in this >> respect >> and please note that any disclosure, copy, distribution or use of the >> contents >> of this message is prohibited and may be unlawful. We have taken every >> reasonable precaution to ensure that any kind of attachment to this >> e-mail >> has been swept for viruses. However, we cannot accept liability for any >> damage sustained as a result of software viruses and would advise that >> you carry out your own virus checks before opening any attachment. >> _______________________________________________ >> Help-glpk mailing list >> [email protected] >> http://lists.gnu.org/mailman/listinfo/help-glpk >> >> > > -- View this message in context: http://old.nabble.com/Accessing-shadow-prices-in-stand-alone-LP-Solver-tp22080364p28451647.html Sent from the Gnu - GLPK - Help mailing list archive at Nabble.com. _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
