<div dir="ltr">Hi all,<div><br></div><div>I've been posting a lot recently.. first of all, thank you for replying!</div><div><br></div><div>I've unit tested my application pretty vigorously, and a Cbc API unit test broke when I moved to the CLI implementation. Specifically, I set up the following toy problem:</div>
<div><br></div><div>min 2x + 0.5y + 1.8z</div><div>st x + y > 4.4</div><div> y + z < 3.1</div><div>x in [1.3, 5], y in [1.7, 5], z in [0.4, 5]</div><div>y, z integer<br clear="all">
<div><br></div><div>The unit test originally passed using the OsiCbcSolverInterface's initial solve and branch and bound methods. I updated it to use an OsiClpSolverInterface that is fed a CbcModel and call CbcMain0/1 on said model. The unit test now fails with the following relevant output:</div>
<div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">Welcome to the CBC MILP Solver <br>Version: 2.8.7 <br>
Build Date: Dec 28 2013 <br>command line - exchng -solve -quit (default strategy 1)<br>Continuous objective value is 5.47 - 0.00 seconds<br>Cgl0000I Cut generators found to be infeasible! (or unbounded)<br>Pre-processing says infeasible or unbounded</blockquote>
</div><div><br></div><div>To double check that indeed a feasible solution existed, I solved the maximization form of the same instance. Attached are MPS files for the max and min forms, and I have verified the same behavior using the cbc CLI (i.e., min is returned as infeasible and max solves). </div>
<div><br></div><div>I'm curious if anyone can replicate this and/or has any advice.</div><div><br></div><div>Cheers,</div><div><br></div>-- <br><div dir="ltr">Matthew Gidden<br>Ph.D. Candidate, Nuclear Engineering<div>
The University of Wisconsin -- Madison<br>Ph. 225.892.3192<br></div></div>
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