Model.addGenConstrOr()

addGenConstrOr ( resvar, vars, name="" )

Add a new general constraint of type GRB.GENCONSTR_OR to a model.

An OR constraint <span>$</span>r = \mbox{or}\{x_1,\ldots,x_n\}<span>$</span> states that the binary resultant variable <span>$</span>r<span>$</span> should be <span>$</span>1<span>$</span> if and only if any of the operand variables <span>$</span>x_1,\ldots,x_n<span>$</span> is equal to <span>$</span>1<span>$</span>. If all operand variables are <span>$</span>0<span>$</span>, then the resultant should be <span>$</span>0<span>$</span> as well.

Note that all variables participating in such a constraint will be forced to be binary, independent of how they were created.

You can also add an OR constraint using the or_ function.

Arguments:

resvar (Var): The variable whose value will be equal to the OR concatenation of the other variables.

vars (list of Var): The variables over which the OR concatenation will be taken.

name (string, optional): Name for the new general constraint. Note that name will be stored as an ASCII string. Thus, a name like 'A<span>$</span>{\rightarrow}<span>$</span>B' will produce an error, because '<span>$</span>{\rightarrow}<span>$</span>' can not be represented as an ASCII character. Note also that names that contain spaces are strongly discouraged, because they can't be written to LP format files.

Example usage:

  # x5 = or(x1, x3, x4)
  model.addGenConstrOr(x5, [x1, x3, x4], "orconstr")

  # overloaded forms
  model.addConstr(x5 == or_([x1, x3, x4]), "orconstr")
  model.addConstr(x5 == or_(x1, x3, x4), "orconstr")

Try Gurobi for Free

Choose the evaluation license that fits you best, and start working with our Expert Team for technical guidance and support.

Evaluation License
Get a free, full-featured license of the Gurobi Optimizer to experience the performance, support, benchmarking and tuning services we provide as part of our product offering.
Academic License
Gurobi supports the teaching and use of optimization within academic institutions. We offer free, full-featured copies of Gurobi for use in class, and for research.
Cloud Trial

Request free trial hours, so you can see how quickly and easily a model can be solved on the cloud.

Search