E-IG0106 — Value range with inverted bounds

Error Type	Instance Generation Error
Phase	configuring random instance generation (the default= / options= arguments of Problem.generate_random_dataset / Problem.generate_random_instance)
Python exception	ValueError (builtin)

Message

The value range `{range}` has a lower bound greater than its upper bound, or a bound that is not a number.

Possible fix: adjust the bounds so that the lower bound does not exceed the upper bound and neither bound is `NaN`.

({range} shows the range in mathematical interval notation, e.g. [7, 5))

Cause

The value entry of a random-generation hint was recognized, but its lower bound is greater than its upper bound, so the range could never contain any number — for example (7.0, 5.0) or jm.generation.value.closed(1.0, -1.0). A bound of float("nan") paired with another numeric bound is also rejected here, because nan cannot be ordered against the other endpoint. Ranges that are empty but ordered, such as jm.generation.value.open(1.0, 1.0), are accepted at this point; if such a range is actually used, generation later fails with E-IG0002.

Fix

Swap or widen the bounds so that the lower bound does not exceed the upper bound, and replace any nan endpoint with a real number:

problem.generate_random_dataset(
    options={"c": {"value": (-1.0, 1.0)}},  # not (1.0, -1.0)
)

For a one-sided range, use jm.generation.value.at_least(0.0) or jm.generation.value.at_most(1.0) rather than a nan placeholder bound.

Related

E-IG0105 — accepted forms for value range hints. E-IG0103 — the corresponding error for size ranges. E-IG0002 — an accepted but empty value range fails during generation.