[Cbc] Non-integer values when using primal simplex

[Michael Munday]

Hi all,

I am trying to solve the attached mps file using the command line cbc
program, version 2.8.9.  All of the columns are constrained to be integers
(I think).

When I solve it using the following command:

cbc test.mps.gz -primalS -printi csv -solu test.csv

I get an objective value of 3907198 after about 40s, but test.csv contains
a lot of values which have a fractional part of .5.

However when I run with the command:

cbc test.mps.gz -solve -printi csv -solu test.csv

I get an objective value of 3907349 after about 170s and all of the results
are integers.

I am aware that the results might not be exact integers (
http://list.coin-or.org/pipermail/cbc/2014-June/001367.html), however this
seems a bit extreme.

Am I doing something wrong or have I stumbled into a bug?

Thanks for your help!
Michael
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