valueFunctionIdOf

Identifies the kind of value function applied to the supplied metric, for recording alongside results so that a reader can tell how scores were turned into values.

This names the kind of function and not how it was set up: two logistic functions with different locations and scales share an identifier. Where the settings matter they belong with whatever supplied them, since a value function is not required to describe itself. A function supplied as a lambda has no name of its own and is identified by its generated class, which is stable within a build but not meaningful to a reader.