[Coin-lpsolver] Clp Problems

[John J Forrest]

Kyle,

What it means is that the code expects a variable at its lower bound to 
have a positive reduced cost or at least >= -tolerance.  An assert failure 
would tend to indicate that the problem is badly scaled.

However the solution is to refresh your copy of Clp.  That assert is now 
at line 2084 AND commented out.  I did that some weeks ago as for some 
reason CBC was being handed nastier problems - maybe because of changes to 
cut generators.

If you still have problems please send me more information.

John Forrest



Kyle Ellrott <kellrott at csbl.bmb.uga.edu> 
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01/10/2005 01:50 PM

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[Coin-lpsolver] Clp Problems






I'm currently working on some software that uses the Cbc module to 
solve an integer programming problem.  While I'm not confident that my 
constraint matrix has been set up correctly, as far as I know, it 
should be fine.
I was wondering if anyone could help figure out what set of events 
would trigger the following assertion:

ClpSimplexDual.cpp:2031: failed assertion 
`oldValue>=-dualTolerance_*1.0001'

What kind of problems is their assertion typically in response to?

Thanks,

Kyle

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