Hello Francesco, unfortunately it is unclear from you message whether you are using the glpsol standalone solver or the GLPK library.
glpsol will by default use branch and bound. If you want to use branch and cut, you have to specify command line parameter --cuts. If you want to solve the LP relaxation only, specify --nomip. If you are using the GLPK library glp_simplex solves the LP relaxation, glp_intopt uses branch and bound or branch and cut depending the values you pass in structure glp_iocp. Please, read the manuals provided with GLPK: glpk-4.47/doc/glpk.pdf glpk-4.47/doc/gmpl.pdf The manuals are contained in the source distribution of GLPK available for download from ftp://ftp.gnu.org/gnu/glpk/glpk-4.47.tar.gz Best regards Xypron -------- Original-Nachricht -------- > Datum: Fri, 04 Nov 2011 01:53:24 +0300 > Betreff: [Help-glpk] [Fwd: Binary programming and simplex] > -------- Forwarded Message -------- > From: Francesco Arneodo <[email protected]> > To: [email protected] > Subject: Binary programming and simplex > Date: Thu, 3 Nov 2011 16:27:17 +0100 > > Hello, > I am using GLPK to solve a binary problem with 11,000 variables. > I use the simplex method and it seems to work fine. However, I thought > that binary problems are best solved with the branch and cut method > and I have difficulty in understanding how the simplex tackles a > binary problem. > What GLPK does? I mean, it really uses the simplex method, or seeing > that it's a binary problem automatically switches to branch and cut? > Thanks, > > > > Francesco Arneodo > INFN - Laboratori Nazionali del Gran Sasso > Assergi 67100 L'Aquila - Italy > tel. +39 0862 437-207 mobile (-825) > fax +39 0862 437570 > Skype: frnz65 > > > > > > _______________________________________________ > Help-glpk mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/help-glpk -- Follow me at http://twitter.com/#!/xypron NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie! Jetzt informieren: http://www.gmx.net/de/go/freephone _______________________________________________ Help-glpk mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-glpk
