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Simple LP problem

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4 comments

  • Matthias Miltenberger
    Gurobi Staff Gurobi Staff

    Hi James,

    Some variables are not defined (sigT, B, and F), so it's hard to see why the model would be infeasible and your code is also not reproducible.

    I recommend you write out the generated model as LP file and check whether it is actually what you intended to model:

    m.write('model.lp')

    Cheers,
    Matthias

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  • James Whiteley
    Gurobi-versary
    First Comment
    First Question

    Thanks Matthias for the advice re. m.write()

    I am looking into it now!

    James 

    0
  • Thomas Opfer
    Gurobi-versary
    Collaborator

    In addition to that, the warning

    Warning for adding constraints: zero or small (< 1e-13) coefficients, ignored

    indicates that you might have run into numerical trouble when creating the model.

     

    Maybe, you can scale your coefficients to some reasonable range. If not, it might become hard to solve your problem using a floating point solver like Gurobi.

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  • James Whiteley
    Gurobi-versary
    First Comment
    First Question

    Hi Thomas,

    'might have run into numerical trouble when creating the model.' 

    Yes I believe it was this, an error in B somewhere. Have managed to solve this now, thanks!

    James 

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