Hi All,<br><br>Never mind, the previous email I have found the problem. I was generating global cuts<br>when I was not supposed to (I was generating cuts for a non-convex curve). <br><br><br>Pete<br><br><br><div class="gmail_quote">
On Thu, Apr 22, 2010 at 12:45 AM, Pete Janes <span dir="ltr"><<a href="mailto:ppjanes@gmail.com" target="_blank">ppjanes@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi All,<br><br>I need some debugging help with Couenne. I am coding another specialized function <br>
for Couenne (The Two-Electron Repulsion Integral) which I plan to use for quantum<br>chemistry problems.<br><br>I am getting the wrong results, and I have narrowed the problem down to cut generation.<br>
Here is the background. In Cbc, the main function which processes a node is doOneNode(). <br>This step first solves the linear programming problem associated with the node given the<br>new variable bounds, then if everything is still feasible it adds more cuts to the LP by calling<br>
CouenneCutGenerator::generateCuts.<br><br>void CouenneCutGenerator::generateCuts (const OsiSolverInterface &si,<br> OsiCuts &cs, const CglTreeInfo info)<br><br>The problem I am having is not that my code generates the wrong cuts, but the initial cuts inside<br>
OsiCuts &cs are wrong. These cuts come from a prior cut generation step and it should NOT be<br>included for the current step (if you can visualize an auxiliary expression as a curve, this prior cut<br>cuts straight through it).<br>
<br>Does anyone know the likely cause of this problem? I am sure this has been encountered before<br>during debugging of Couenne.<br><br>Thanks a lot in advance,<br><font color="#888888"><br>Pete<br>
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