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Hi, <br>
I developp a branch and cut algorithm with BCP (with OSI/CLP).<br>
Each iteration, the linear program is solved and then if it is
feasible, the solution is tested to know if it is a solution a the
ILP... So, in the method test_feasibility(..), we first have to check
if the LP was feasible (in order to not test a solution if there
doesn't exist anyone).<br>
So, as in the François Margot's example (.../COIN/Example/BAC/), I have
first test<br>
<i>
if(getLpProblemPointer()->lp_solver->isProvenPrimalInfeasible())
return(0);</i><br>
(I don't test if I'm during strong branching but I don't think it is
the reason of the bugs)<br>
<br>
But I have encountered several bugs. I have to change the test by :<br>
<i> if((getLpProblemPointer()->lp_solver->isProvenPrimalInfeasible())
|| (getLpProblemPointer()->lp_solver->isDualObjectiveLimitReached
()) || (getLpProblemPointer()->lp_solver->isIterationLimitReached
()) || (getLpProblemPointer()->lp_solver->isAbandoned ()))<br>
return(0);</i><br>
<br>
And I have to comment the throw error's line in the code's lines
(130-133) in the file BCP_lp_main_loop.cpp : <br>
<i> if (tc & BCP_Abandoned) {<br>
// *FIXME* : later we might want to prune this node, but
continue<br>
//### throw BCP_fatal_error("LP solver abandoned
the lp.\n");<br>
}</i><br>
<br>
I'm not sure understanding why it isn't sufficient to only test
feasibility with BAC example's test...<br>
In any case, the new test and the comment line seems to allow the
program working well.<br>
<br>
Best regards, <br>
<br>
Mathieu LACROIX<br>
<br>
<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
Mathieu LACROIX
<a class="moz-txt-link-abbreviated" href="mailto:mathieu.lacroix@isima.fr">mathieu.lacroix@isima.fr</a>
Université Blaise Pascal - Clermont Fd II
Laboratoire LIMOS
Bâtiment ISIMA - Bureau D112
Complexe scientifique des Cézeaux
63 177 Aubière, Cedex - France
Tel : 04.73.40.79.48
Fax : 04.73.40.76.39
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