[Cbc] Artificial variables

[Christos]

I forgot to mention that it is a minimization problem , so i do not know 
if there is any point in limiting objective.

Sorry for the double mail.

On 10/8/2012 19:24, acw at ascent.com wrote:
> 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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