Re: [Help-glpk] [Fwd: Binary programming and simplex]

[glpk xypron]

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 <address@hidden>
> To: address@hidden
> 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
> address@hidden
> https://lists.gnu.org/mailman/listinfo/help-glpk

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