CPM is the cutting plane method (branch and cut).<br>
<br>
PC is price and cut.<br>
<br>
Using those settings (below) you are randomly selecting the relaxation to be 1/3 of
the original problem. I am not surprised it is much slower than Cplex.
This has very little chance of performing well and is only there for the sake
of illustration and testing. <br><br>If you know the problem has some structure, you should
provide that structure using the MILPBlock application. <br><br><br><br>To answer your other questions:<br><br>> I am wondering if Dip expects that all the bound on variables being explicitly declared as constraints or?<br>
<br>No.<br>
<br><br>> Is there any specific strategy to deal with bigM model in DIP, in particular?<br><br>Nothing specific. In fact, DIP does not have a presolver activated (this is on Ted's ToDo List). So, a poorly formulated bigM model will likely perform badly - since bigM is typically taken care of in the presolver.<br>
<br><br><br><br><br><br>
<br><br>On Fri, Sep 16, 2011 at 8:58 AM, Shahin Gelareh <span dir="ltr"><<a href="mailto:shahin.gelareh@gmail.com">shahin.gelareh@gmail.com</a>></span> wrote:<br>The setting in param of MILP example project is:<div>
I Assume it is Price and cut (PC) but I dont know what you mean by CPM (Cutting plance only?)?</div><div><br></div><div>#{0,1}: use DECOMP for price and cut
<div>doPriceCut = 1 </div><div><br></div><snip><br><br><div># Name of MPS file for instance (assumed to be in DataDir).</div>
<div>Instance = Scheduling</div><div><br></div><div># Seed for the random number generator (for choosing rows).</div><div>RandomSeed = 1</div><div><br></div><div># Percentage of rows (randomly chosen) for relaxation.</div>
<div>RelaxPercent = 0.33</div></div><br><br><br>On Fri, Sep 16, 2011 at 2:42 PM, Matthew Galati <span dir="ltr"><<a href="mailto:matthew.galati@gmail.com" target="_blank">matthew.galati@gmail.com</a>></span> wrote:<br>
<div>What algorithm are you using?</div><div><br></div><div>CPM or PC?<br><br><br><br><br></div><br><br><div class="gmail_quote">On Fri, Sep 16, 2011 at 6:08 AM, Matthew Galati <span dir="ltr"><<a href="mailto:matthew.galati@gmail.com">matthew.galati@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Please send me the example.<br>
<br>
Sent from my iPhone<br>
<div><div></div><div class="h5"><br>
On Sep 16, 2011, at 2:32 AM, Shahin Gelareh <<a href="mailto:shahin.gelareh@gmail.com">shahin.gelareh@gmail.com</a>> wrote:<br>
<br>
> Hi,<br>
><br>
> I am wondering if Dip expects that all the bound on variables being explicitly declared as constraints or?<br>
> I have got a Big-M model which is solved fine on Cplex in 5 seconds for an small instance but when I feed it into the MILP example takes time for ever and my application also fails .<br>
> Adding explicit did not make things better but sill the question remains.<br>
> Is there any specific strategy to deal with bigM model in DIP, in particular?<br>
><br>
> regards,<br>
</div></div>> _______________________________________________<br>
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</blockquote></div><br>