[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Help-glpk] Setting initial integer solution in GLPSOL
From: |
xypron |
Subject: |
[Help-glpk] Setting initial integer solution in GLPSOL |
Date: |
Sun, 14 Dec 2008 14:50:40 -0800 (PST) |
Hello Andrew,
I would like to set the integer values of a possible solution in glpsol such
that this solution is used as a starting point for the branch and cut
solver. I do not want to preset the non integer values.
I have patched glpk-4.34 such that variable values can be preset, e.g.
var x := 4;
The changed files and diffs can be downloaded from
http://glpk.dyndns.org/viewvc/svn/glpk/glpk/branches/glpk-4.34-dot/
Changes (including changes for outputting dual values) are in
include/glpmpl.h
src/glpapi16.c (only changes for output of dual values)
src/glpmpl01.c
src/glpmpl03.c
src/glpmpl04.c (only changes for output of dual values)
What is missing, are the necessary changes to glpsol (glpapi17.c).
Would this be a correct implementation:
Create a callback routine. Pass it as parm.cb_func to glp_intopt.
In the callback routine react to the first call
with reason GLP_IHEUR as follows:
- Preset the integer variables in tree->mip.
- Initialize parameters: glp_init_smcp(&parm);
- Set parameters: parm.meth = GLP_DUALP;
- Solve the LP: ret = glp_simplex(tree->mip, &parm);
- Pass all variables with a call to glp_ios_heur_sol.
Is this a feature you would be willing to integrate into the distribution?
Best regards
Xypron
--
View this message in context:
http://www.nabble.com/Setting-initial-integer-solution-in-GLPSOL-tp21005682p21005682.html
Sent from the Gnu - GLPK - Help mailing list archive at Nabble.com.
- [Help-glpk] Setting initial integer solution in GLPSOL,
xypron <=
- Re: [Help-glpk] Setting initial integer solution in GLPSOL, Andrew Makhorin, 2008/12/15
- Re: [Help-glpk] Setting initial integer solution in GLPSOL, Oscar Gustafsson, 2008/12/15
- Re: [Help-glpk] Setting initial integer solution in GLPSOL, Andrew Makhorin, 2008/12/15
- Re: [Help-glpk] Setting initial integer solution in GLPSOL, Oscar Gustafsson, 2008/12/15
- Re: [Help-glpk] Setting initial integer solution in GLPSOL, xypron, 2008/12/15
- Re: [Help-glpk] Setting initial integer solution in GLPSOL, Ali Baharev, 2008/12/16
- Re: [Help-glpk] Setting initial integer solution in GLPSOL, Oscar Gustafsson, 2008/12/17