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Re: [Bug-glpk] [Fwd: MIP solver bug]
From: |
Chris Matrakidis |
Subject: |
Re: [Bug-glpk] [Fwd: MIP solver bug] |
Date: |
Thu, 12 Jan 2017 15:20:49 +0200 |
Hi Emma,
> In this case, the default branching works better than pseudocost branching.
> However, in general the original problem is much slower than the previous one
> (lp_modified.txt by removing x[0.0])
In general, pseudocost branching is considered more accurate, but
needs more time for initialisation. However there is no guarantee that
this holds for any problem.
Moreover, I see that your problem is not very well scaled (although a
lot better than with big M):
A: min|aij| = 1.307e-009 max|aij| = 7.569e+005 ratio = 5.792e+014
Can you change the formulation to reduce the range of values in the constraints?
Best Regards,
Chris Matrakidis
Re: [Bug-glpk] [Fwd: MIP solver bug], Heinrich Schuchardt, 2017/01/06