[Cbc] Artificial variables

[acw at ascent.com]

No single constraint is responsible for an infeasibility.  Consider a 
system with one variable, and two constraints, X >= 7 and X <= 4.  This 
system is obviously infeasible, but which of the two constraints is at 
fault?

In your case I suspect that the problem is unbounded rather than 
infeasible, because you have so few constraints and so many variables. 
Unless the problem has a very special structure, a problem with fewer 
constraints than variables is likely to be unbounded.

You can check this by adding a constraint that limits your objective to, 
say, 1e6.  If the problem now solves, then unboundedness is almost 
certainly your difficulty.



From:
Christos <chtsolak at gmail.com>
To:
cbc at list.coin-or.org
Date:
08/10/2012 09:32 AM
Subject:
[Cbc] Artificial variables



Hi, i have a model with around 10000 variable and 1500 equations.

But i get the messages on the photo when i run it:
http://imageshack.us/photo/my-images/39/dascd.png/

Is there any way to use artificial variable or something else in order 
to find the problematic equation?

Thank you in advance
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