Decision Optimization

Decision Optimization

Delivers prescriptive analytics capabilities and decision intelligence to improve decision-making.


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  • 1.  Detecting redundant constraints

    Posted 12/13/13 04:25 AM

    Originally posted by: veronicads


    Hello!

    I'm implementing a sort of Fourier-Motzkin elimination using the Python API and CPLEX 12.4. This means that i'm adding a huge number of constraints to my problem but most likely some of them are redundant. Is there a way to detect redundant constraints for the formulation? That is, is there a way I can check if a constraint cuts off a part of the feasible region?

    Thanks for your help,

    Veronica


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  • 2.  Re: Detecting redundant constraints

    Posted 12/13/13 09:27 AM

    This does not answer your question but you could define your constraints as lazy constraints so that they are only pulled into the model when they are violated. Maybe this is already good enough for you?


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  • 3.  Re: Detecting redundant constraints

    Posted 12/13/13 11:07 AM

    Originally posted by: veronicads


    Is it possible to add lazy constraints also if my problem has only continuous variables? 


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  • 4.  Re: Detecting redundant constraints

    Posted 12/15/13 08:13 AM

    Yes, that should work. It will solve your problem as a MIP but that should not matter since the LP relaxation is then always integer feasible. Note that in the C-API you would have to explicitly declare your problem to be a MIP but since you are using Python the solve() method will do that for you.


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