Bounds for Variable

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ALESSANDRA VIEIRA

2024年02月09日 10:03 編集済み

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I am using Gurobi 9.0, with C++. I am trying to put an array element, that is created for a C++ function ( use random) as a UPPER bound of a GRB Var array, as follows:

for ( t = 0; t < z; t++) {
    ostringstream vname;
    vname << "Wcurt" << t;
    // Wcurt[t].set(GRB_CharAttr_VType,GRB_INTEGER);
    Wcurt[t].set(GRB_DoubleAttr_UB, P_wind[t]);
    Wcurt[t].set(GRB_DoubleAttr_LB, 0);
    Wcurt[t].set(GRB_StringAttr_VarName, vname.str());
}

P_Wind[t], is a float array type;
W_curt can be continuous;

 

I appreciate any help.
Best regards,

 

As a syntax, what means the C++ syntax is wrong, however that also has to do with the GRBVar is created, meaning as also an array.

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  Matthias Miltenberger

  • Gurobi Staff

  2024年02月09日 10:46

  Hi Alessandra!

  I am not sure I understand the problem or the error here. Could you please share a minimal reproducible example, including the error message?

  Thanks,
  Matthias

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  ALESSANDRA VIEIRA

  2024年02月09日 15:03

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  Hi Matthias,

  The problem is my array P_wind is one single function output, that was randomly chosen from one data  2-D array [T][N] that will be the Upper Bound (UB) for the Gurobi variable W_curt[ ], my code is Gurobi C++ in VS. I just one be sure, is not problematic for a GRB_VAR have such output as UB.

  I would be very kind, to let me know about it.

  Best Regards,

  Alessandra

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  Matthias Miltenberger

  • Gurobi Staff

  2024年02月09日 16:46

  Hi Alessandra,

  This should be fine. Just be aware that you cannot have dynamically changing values (e.g. the output of a function that is part of your problem) as model parameters. The upper bound has to be a fixed value for Gurobi.

  I hope that answers your question.

  Cheers,
  Matthias 

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