[Top][All Lists]

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

[Help-glpk] Re: Fwd: Degeneracy problem

From: Andrew Makhorin
Subject: [Help-glpk] Re: Fwd: Degeneracy problem
Date: Fri, 14 Jan 2011 15:01:58 +0300

On Tue, 2011-01-11 at 22:04 -0800, Abbas Ebadi wrote:
> ---------- Forwarded message ----------
> From: Abbas Ebadi <address@hidden>
> Date: Mon, 10 Jan 2011 04:12:55 -0800
> Subject: Degeneracy problem
> To: address@hidden
> Dear Mr or Madam,
> I am using the GLPK solver for solving an LP model in GAMS. At primary
> iterations, it improves the value of objective function rapidly but,
> then, solution process continues so long and very slow progress
> happens. I was wondering how I can prevent the solver to continue
> solving process when such cases happen.
> Kind Regards,
> Abbas Ebadi

This may happen if your lp instance is highly degenerate. You can try to
increase the feasibility tolerance (tol_bnd) or use the dual simplex (by
default the primal simplex is used). Does the glpk simplex solver solve
the instance to optimality, or it stalls with no progress?

reply via email to

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