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Re: [Help-glpk] is it possible to determine the value a nb variable will
From: |
Michael Hennebry |
Subject: |
Re: [Help-glpk] is it possible to determine the value a nb variable will take? |
Date: |
Tue, 30 Dec 2008 11:43:51 -0600 (CST) |
User-agent: |
Alpine 1.00 (DEB 882 2007-12-20) |
On Mon, 29 Dec 2008, Selçuk Cihan wrote:
It calculates amounts by which variable bounds may be changed in the
original problem while the optimal basis remains the same.
i am working with suboptimal solutions, lpx_print_sens_bnds() is of no
use for me i guess, it just tells me that i do not have an optimal
solution.
I think that GLPK has a mechanism for getting a column of the simplex tableau.
That should add enough information to get you what you want.
i am not sure if i made myself clear, due most probably to my lack of
experience in linear programming. what i need is, to be able to
implement my own iterative algorithm, for solving a 0-1 integer
program. The iterations will start from the optimal solution of the LP
relaxation of the 0-1 integer program. At each iteration i will select
a nonbasic variable and make it enter to the basis. That is called a
move.
If you get it working at all, I'd like to see it.
I have some integer programming ideas that would also
require thorough control over the simplex method.
With GLPK, I have usually used the API because
LP was part of a larger algorithm.
The larger algorithm did not require tinkering with the internals of LP.
--
Michael address@hidden
"Pessimist: The glass is half empty.
Optimist: The glass is half full.
Engineer: The glass is twice as big as it needs to be."