|
From: | Domingo Alvarez Duarte |
Subject: | Re: Regression between 4.61 and 4.65 for problems which can be preprocessed to almost nothing |
Date: | Tue, 14 Jul 2020 09:52:36 +0200 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 |
Hello Chris !
Thank you for pointing out !
Running the converted problem to "mps" format through https://github.com/lgottwald/PaPILO give this output:
=====
papilo presolve -f s.mps
reading took 0.00459 seconds
starting presolve of problem s.mps:
rows: 81
columns: 48 (48 int., 0 cont.)
nonzeros: 168
presolve detected infeasible problem
=====
But glpsol do not do the same.
Cheers !
On Mon, 13 Jul 2020 at 19:32, Domingo Alvarez Duarte <mingodad@gmail.com> wrote:- if (mip->m == 0 && mip->n == 0)
+ if (mip->m == 0 || mip->n == 0)
This is not a correct change, if m==0 && n>0 then the problem is unbounded. Checking only if n=0 seems to do what is needed here, However a deeper look is needed to figure out if there are any implications.
Best Regards,
Chris Matrakidis
[Prev in Thread] | Current Thread | [Next in Thread] |