[Clp] How to get integral solution for totally unimodular matrix?

[Lasse Kliemann]

* Message by -John J Forrest- from Wed 2009-06-24:
 
> If you replace the initialSolve by resolve, then the problem goes away.
> However the long thin strategy is 50 times faster!
> 
> To get good performance and normal simplex characteristics you need to add
> ten lines.  I attach a modified integral.cpp.

Thank you, John, for the explanation and the example code.

I ran it, but it keeps complaining about an empty problem:

   Clp3002W Empty problem - 250 rows, 0 columns and 0 elements

The problem *is* loaded via 'assignProblem'; I also tried:

   si->getModelPtr()->loadProblem(*matrix, col_lb, col_ub,
        objective, row_lb, row_ub);

to no avail.


Thank you for a hint.
Lasse
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