[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Help-glpk] post-processing without defined variables?

From: Kevin Hunter
Subject: [Help-glpk] post-processing without defined variables?
Date: Sat, 30 Jun 2012 19:52:41 -0400
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1

Hello GLPK List,

I see from the GLPK Wikibook that there's no ability to create reporting variables (err, just learned that others call them "defined variables").

I want to explore the last sentence in that section ("But you can use a structural variable and a constraint instead to achieve the same effect — the downside being that this formulation may render your problem harder to solve"). The models that I'm working with are necessarily large (roughly 1e5 [C] x 1e5 [R], give or take an order of magnitude depending on the input), and I'd like to avoid adding any more variables to the solver's matrix.

Given that I can't create constraints /after/ a solve statement (i.e. to re-solve starting from the previous solution), does that mean that my only option is a post-GMPL step with another tool (e.g. C, Perl, Python)?



reply via email to

[Prev in Thread] Current Thread [Next in Thread]