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GRBModel::addGenConstrLogA()
Add a new general constraint of type GRB_GENCONSTR_LOGA to a model.
A logarithmic function constraint states that the relationship should hold for variables and , where is the (constant) base.
A piecewise-linear approximation of the function is added to the model. The details of the approximation are controlled using the following four attributes (or using the parameters with the same names): FuncPieces, FuncPieceError, FuncPieceLength, and FuncPieceRatio. Alternatively, the function can be treated as a nonlinear constraint by setting the attribute FuncNonlinear. For details, consult the General Constraint discussion.
GRBGenConstr | addGenConstrLogA ( | GRBVar | xvar, |
GRBVar | yvar, | ||
double | a, | ||
std::string | name="", | ||
std::string | options="" ) |
Arguments:
xvar: The variable.
yvar: The variable.
a: The base of the function, .
name (optional): Name for the new general constraint.
options (optional): A string that can be used to set the attributes that control the piecewise-linear approximation of this function constraint. To assign a value to an attribute, follow the attribute name with an equal sign and the desired value (with no spaces). Assignments for different attributes should be separated by spaces (e.g. "FuncPieces=-1 FuncPieceError=0.001").
Return value:
New general constraint.
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