[Coin-discuss] Correct use of CglPreProcess with CbcModel?

[John J Forrest]

James,

Try the second way of using CglPreProcess as given in sample2.cpp.  This 
uses CbcStrategy and passes that in to Cbcmodel.  So CbcModel handles 
copies of solvers.  If that has a memory leak tell me and I will fix.

John Forrest



"James Gibbons" <James.Gibbons at nottingham.ac.uk> 
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03/28/2006 08:46 AM
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[Coin-discuss] Correct use of CglPreProcess with CbcModel?






Hi,

I'm having some problems using CglPreProcess and CbcModel together. My 
code involves modifying a matrix, solving and changing the many times. My 
code works but it leaks memory until eventually all memory is exhausted. 
The essentials of the code are at the end of this message (note though 
that in my application the LP solve and global solver are in different 
functions, and heuristics and cuts are used). To my naive eye it looks 
like I need to delete solver1 as preProcess returns a new solver instance, 
but this causes a crash. I'm happy to go about things in a different way 
if anyone can recommend an alternative. However, CglPreProcess does reduce 
the time to find a solution for me so I'd like to keep using it,

Thanks,
James

//code as follows

solver0_(new OsiClpSolverInterface());
solver0_->readLp(filename_.c_str(),1e-08);

for(int i=0;i<numRuns;++i) {

                 //LP solve function
                 solver0_->intitalSolve();
 
                 //Global solve function
                 CglPreProcess pinfo1;
                 OsiSolverInterface *solver1 = 
pinfo1.preProcess(*solver0_,false,15);
                 CbcModel model(*solver1);

                 //add cuts and heuristics to model

                 model.branchAndBound();
                 model.deleteObjects();          //is this necessary?
                 pinfo1.postProcess(*model.solver());
                 //delete solver1;               //causes crash   

                 //my update matrix function
                 updateMatrix();
}

delete solver0_;






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