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<p>Hi Abdelkader,</p>
<p>you wrote that you have used the transformed ones, but for me it works in my pricing by means of functions SCIPgetTransformedCons() and SCIPgetDualsolLinear(). They are used in VRP example.</p>
<p>Sorry if this is not new information for you.</p>
<p>Diego.</p>
<p> </p>
<div> </div>
<p>El 17/10/2014 01:26, Abdelkader Ouali escribió:</p>
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<div dir="ltr"><span style="font-size: medium; color: #000000; font-family: Calibri, sans-serif;"><br id="FontBreak" /></span>Hi Rodolfo,
<div> </div>
<div>Thank's for reply.</div>
<div> </div>
<div>
<div>But when applying pricing, we use dual values to get the reduced cost,</div>
<div>in my case, i don't get the correct values of dual variables.</div>
<div>The earlier example is one iteration of column generation, at these step</div>
<div>scip found the optimal solution of the master problem, so no need to generate new columns,</div>
<div>the problem is that the value of dual variable are all zero, which is not correct, and scip</div>
<div>continue to generate new columns.</div>
</div>
<div> </div>
<div>So how we can get dual variables in pricing if scip don't provide dual information ? </div>
<div> </div>
<div>Best regards</div>
<div> </div>
<div>A. Ouali </div>
<div> </div>
<div> <br /><br />
<div><hr id="stopSpelling" />Date: Thu, 16 Oct 2014 18:17:20 -0300<br />Subject: Re: [Scip] Getting duals values of best solution<br />From: rodolfo.carvajal@gmail.com<br />To: oualiaek@hotmail.fr<br /><br />
<p dir="ltr">Hi Abdelkader,<br /> If you solve your MIP as a SCIP problem, you don't get dual information (see the SCIP FAQ <a href="http://scip.zib.de/#faq">http://scip.zib.de/#faq</a>).<br /> You can use the LP interface (lpi/lpi.h) to interact with the LP solver and get the duals.</p>
<p dir="ltr">Hope this helps,<br /> Rodolfo</p>
<div class="ecxgmail_quote">On Oct 16, 2014 5:49 PM, "Abdelkader Ouali" <<a href="mailto:oualiaek@hotmail.fr">oualiaek@hotmail.fr</a>> wrote:<br />
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<div dir="ltr">Dear scip users,
<div><br />
<div>
<div>I have a short example of ILP, and i want to know how to get dual values of optimal solution,</div>
<div>when i use cplex, it give me the correct value of dual variables,</div>
<div>but when using scip the dual values is all zero, knowing that i set the pointers of constraint to the transformed</div>
<div>ones, in attachment you will find source code containing the example and how i do to get the dual values.</div>
<div> </div>
<div>I want to know what is wrong in this code ?</div>
</div>
<div> </div>
<div>Best regards</div>
<div> </div>
<div>A. Ouali </div>
</div>
</div>
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