Model.addGenConstrPow()
addGenConstrPow ( xvar, yvar, a, name="", options="" )
Add a new general constraint of type GRB.GENCONSTR_POW to a model.
A power function constraint states that the relationship 
should hold for variables 
and 
, where 
is the
(constant) exponent.
The lower bound of variable must be nonnegative, even if is an integer.
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, FuncPiecesLength, and FuncPieceRatio. For details, consult the General Constraint discussion.
Arguments:
xvar (Var): The variable.
yvar (Var): The variable.
a (float): The exponent of the function, 
.
name (string, optional): Name for the new general constraint.
options (string, 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.
Example usage:
# y = x^3.5 gc = model.addGenConstrPow(x, y, 3.5, "gf", "FuncPieces=1000")
