addRange ( expr, lower, upper, name="" )
Add a range constraint to a model. A range constraint states that the
value of the input expression must be between the specified
upper bounds in any solution.
Note that range constraints are stored internally as equality
constraints. We add an extra variable to the model to capture the
range information. Thus, the
attribute on a range
constraint will always be
In particular introducing a range constraint
expr: Linear expression for new range constraint. Can be a Var or a LinExpr.
lower: Lower bound for linear expression.
upper: Upper bound for linear expression.
name: Name for new constraint. Note that name will be stored as an ASCII string. Thus, a name like 'AB' will produce an error, because '' 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.
New constraint object.
# 1 <= x + y <= 2 model.addRange(x + y, 1.0, 2.0, "range0") # overloaded forms model.addConstr(x + y == [1.0, 2.0], name="range0")