E-CE0600 — Non-numeric value in a fixed-variables dictionary

Error Type	Compile Error
Phase	configuring fixed_variables for evaluation
Python exception	TypeError (builtin)

Message

Each value in the dictionary fixing an indexed variable in `fixed_variables` must be an `int` or `float`, but got `{type_name}`.

Possible fix: map every subscript to a numeric value.

({type_name} is the Python type of the offending value)

Cause

An entry in the fixed_variables argument (of Problem.eval, Problem.generate_random_instance, or the Compiler constructor) fixes an indexed decision variable with a dictionary mapping subscripts to values, and one of those values could not be converted to a number. For example, fixed_variables={"x": {(0, 1): "one"}} raises this error because "one" is not numeric. Besides int and float, values that support numeric conversion, such NumPy numeric scalars, are also accepted; strings are not, even if they spell a number.

Fix

Map every subscript to an int or float:

problem.eval(
    instance_data,
    fixed_variables={"x": {(0, 1): 1.0, (0, 2): 0.0}},
)

If the values come from a solver result or a data frame, convert them to plain numbers (e.g. with float(v)) before building the dictionary.

Related

E-CE0601 — the key (subscript) side of the same dictionary is invalid. E-CE0602 — the whole entry for a variable is neither a number nor a dictionary.