ribs.emitters.rankers.TwoStageObjectiveRanker¶

class ribs.emitters.rankers.TwoStageObjectiveRanker(seed: int | integer | None = None)[source]¶

Ranks solutions based on status and on objective values.

This ranker is similar to ribs.emitters.rankers.ObjectiveRanker, but ranks newly added solutions before improved solutions.

This ranker originates in the optimizing emitter in Fontaine 2020.

Methods

rank(emitter, archive, data, add_info)	Ranks solutions based on their objective values, while prioritizing newly added solutions.
reset(emitter, archive)	Resets the internal state of the ranker.

rank(emitter: EmitterBase, archive: ArchiveBase, data: dict[str, ndarray], add_info: dict[str, ndarray]) → tuple[ndarray, ndarray][source]¶

Ranks solutions based on their objective values, while prioritizing newly added solutions.

Parameters:¶

emitter: EmitterBase¶

Emitter that this ranker object belongs to.

archive: ArchiveBase¶

Archive used by emitter when creating and inserting solutions.

data: dict[str, ndarray]¶

Dict mapping from field names like solution and objective to arrays with data for the solutions.

add_info: dict[str, ndarray]¶

Information returned by an archive’s add() method.

Returns:¶

The first array (shape (batch_size,)) is an array of indices representing a ranking of the solutions and the second array (shape (batch_size,) or (batch_size, n_values)) is an array of values that this ranker used to rank the solutions. batch_size is the number of solutions and n_values is the number of values that the rank function used.

reset(emitter: EmitterBase, archive: ArchiveBase) → None¶

Resets the internal state of the ranker.

Parameters:¶

emitter: EmitterBase¶

Emitter that this ranker object belongs to.

archive: ArchiveBase¶

Archive used by emitter when creating and inserting solutions.