[Clp] manual pivoting

[John Forrest]

In your configure add to CXXDEFS -DCLP_USER_DRIVEN1 and code up
functions such as  userChoiceValid1.  You will find definitions at top
of ClpSimplexPrimal.cpp

Then you can use that to return false if pivot element too small.

Option has not really been tested so ask for help if necessary.

John Forrest



On Tue, 2011-05-03 at 22:32 -0500, Kibaek Kim wrote:
> Hi everyone, 
> 
> 
> I am using Clp to manually perform pivots. For a given vertex, I am
> checking every adjacent vertices based on the basis information.
> 
> 
> To do that, my solver
> calls OsiClpSolverInterface::primalPivotResult( ... ). But the solver
> sometimes gives an error. The error occurs in ClpSimplexPrimal.cpp
> line 2927, which indicates CoinAssert (fabs(alpha_) > 1.0e-8).
> 
> 
> I guess the error occurs when pivoting step size is too small. Is that
> right? If so, is there any way to properly handle this?
> 
> 
> Thanks in advance,
> 
> 
> Kibaek
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