Common Warnings/Errors

Warnings

W1001: Setting Var value not in domain

When setting Var values (by either calling Var.set_value() or setting the value attribute), Pyomo will validate the incoming value by checking that the value is in the Var.domain. Any values not in the domain will generate this warning:

>>> m = pyo.ConcreteModel()
>>> m.x = pyo.Var(domain=pyo.Integers)
>>> m.x = 0.5
WARNING (W1001): Setting Var 'x' to a value `0.5` (float) not in domain
     Integers.
     See also https://pyomo.readthedocs.io/en/stable/errors.html#w1001
>>> print(m.x.value)
0.5

Users can bypass all domain validation by setting the value using:

>>> m.x.set_value(0.75, skip_validation=True)
>>> print(m.x.value)
0.75

W1002: Setting Var value outside the bounds

When setting Var values (by either calling set_value() or setting the value attribute), Pyomo will validate the incoming value by checking that the value is within the range specified by Var.bounds. Any values outside the bounds will generate this warning:

>>> m = pyo.ConcreteModel()
>>> m.x = pyo.Var(domain=pyo.Integers, bounds=(1, 5))
>>> m.x = 0
WARNING (W1002): Setting Var 'x' to a numeric value `0` outside the bounds
    (1, 5).
    See also https://pyomo.readthedocs.io/en/stable/errors.html#w1002
>>> print(m.x.value)
0

Users can bypass all domain validation by setting the value using:

>>> m.x.set_value(10, skip_validation=True)
>>> print(m.x.value)
10

Errors

E2001: Variable domains must be an instance of a Pyomo Set

Variable domains are always Pyomo Set or RangeSet objects. This includes global sets like Reals, Integers, Binary, NonNegativeReals, etc., as well as model-specific Set instances. The Var.domain setter will attempt to convert assigned values to a Pyomo Set, with any failures leading to this warning (and an exception from the converter):

>>> m = pyo.ConcreteModel()
>>> m.x = pyo.Var()
>>> m.x.domain = 5
Traceback (most recent call last):
   ...
TypeError: Cannot create a Set from data that does not support __contains__...
ERROR (E2001): 5 is not a valid domain. Variable domains must be an instance
    of a Pyomo Set or convertable to a Pyomo Set.
    See also https://pyomo.readthedocs.io/en/stable/errors.html#e2001