optuna.samplers.nsgaii.BaseMutation

class optuna.samplers.nsgaii.BaseMutation(*args, **kwargs)[source]

Base class for mutations.

A mutation operation is used by NSGAIISampler to mutate a numerical parameter when creating a new individual.

Note

Added in v5.0.0 as an experimental feature. The interface may change in newer versions without prior notice. See https://github.com/optuna/optuna/releases/tag/v5.0.0.

Methods

mutation(param, rng, study, search_space_bounds)

Mutate the given parameter.
abstractmethod mutation(param, rng, study, search_space_bounds)[source]

Mutate the given parameter.

Parameters:

  • param (float) – A parameter value in the transformed numerical search space.

  • rng (np.random.RandomState) – An instance of numpy.random.RandomState.

  • study (Study) – Target study object.

  • search_space_bounds (np.ndarray) – A numpy.ndarray with shape (2,) representing the numerical distribution bounds constructed from transformed search space.

Returns:

A mutated parameter value in the transformed numerical search space.

Return type:

float