[Coin-lpsolver] Problem using setBasisStatus() as a hint for Clp

[John J Forrest]

I have modified code to allow for initial basis.  Does no harm.

Tell me if it helps - if not send a driver and I will get it to work.

John Forrest



js at jeannot.org 
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08/26/2004 04:36 AM

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[Coin-lpsolver] Problem using setBasisStatus() as a hint for Clp






Hi !

I often get the following error when using the Osi setBasisStatus() 
function:
Clp0007I Singular factorization of basis - status -1
Assertion failed: internalFactorize(1)==0, file ClpSimplex.cpp, line 5411

Looking at the code, it seems that ClpSimplex::setBasisStatus() calls
ClpSimplex::statusOfProblem(), which then assert internalFactorize(1)==0.

I use setBasisStatus() to provide a starting point to Clp when doing
initialSolve(), but the basis status I provide may not lead to a correct
factorization (it may not be a basis).

Is there a way to provide an approximate basis status as a hint to Clp ?

Thank you very much in advance,

Regards,

js

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