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Haroldo,<br>
<br>
Is this in trunk or stable?<br>
<br>
I just tried it in trunk and it stopped at line 154 of main.cpp
saying INFEASIBLE. However this is because the code says<br>
<br>
if (ppLP->isProvenOptimal())<br>
{<br>
printf("INFEASIBLE.\n");<br>
exit(1);<br>
}<br>
else<br>
{<br>
printf("Optimal solution found.\n");<br>
}<br>
<br>
which looks the wrong way round. So it seems OK in trunk.<br>
<br>
John Forrest<br>
<br>
<br>
On 20/01/12 18:35, Haroldo Santos wrote:
<blockquote
cite="mid:CACO7Fp2Lbx_VAZCTu5E39wO2_1UKeAbmWnDxqZOEyUo43ck00w@mail.gmail.com"
type="cite"><font face="arial,helvetica,sans-serif">Hi,<br>
<br>
I think I've found a bug in pre-processing phase of CBC.<br>
<br>
What I was doing (and worked flawlessly </font>for all MIPs
except this one) was to inform to CBC a feasible solution found
using a greedy heuristic. This solution was informed considering
variables of the pre-processed model (checking for the original
variables in originalColumns() ).<br>
<br>
What happened is that the pre-processed model for this case
included a new set of constraints (expected) which make this valid
solution to be considered infeasible (unexpected). When I fix the
same set of variables in the original LP there is no problem.<br>
<br>
To make it easy to check for this problem I've wrote a small code
which fixes the same variables in the original and in the
pre-processed problem and made it available here:<br>
<br>
<a moz-do-not-send="true"
href="http://www.decom.ufop.br/haroldo/files/ppBug.tar.gz">http://www.decom.ufop.br/haroldo/files/ppBug.tar.gz</a><br>
<br>
In infRows.txt I listed tree constraints that when removed allows
feasibility to be obtained again.<br>
<br>
Thanks in advance,<br>
<br>
Haroldo<font face="arial,helvetica,sans-serif"><br clear="all">
</font><br>
-- <br>
=============================================================<br>
Haroldo Gambini Santos<br>
Computing Department - Universidade Federal de Ouro Preto - UFOP<br>
email: haroldo [at ] <a moz-do-not-send="true"
href="http://iceb.ufop.br" target="_blank">iceb.ufop.br</a><br>
home/research page: <a moz-do-not-send="true"
href="http://www.decom.ufop.br/haroldo/" target="_blank">www.decom.ufop.br/haroldo/</a><br>
<br>
<br>
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