ribs.emitters.rankers.RankerBase

class ribs.emitters.rankers.RankerBase(seed=None)[source]

Base class for rankers.

Every ranker has a rank() method that returns a list of indices that indicate how the solutions should be ranked and a reset() method that resets the internal state of the ranker (e.g. in RandomDirectionRanker).

Child classes are only required to override rank().

Methods

rank(emitter, archive, data, add_info)

Generates a batch of indices that represents an ordering of data["solution"].

reset(emitter, archive)

Resets the internal state of the ranker.

abstract rank(emitter, archive, data, add_info)[source]

Generates a batch of indices that represents an ordering of data["solution"].

Parameters

  • emitter (ribs.emitters.EmitterBase) – Emitter that this ranker object belongs to.

  • archive (ribs.archives.ArchiveBase) – Archive used by emitter when creating and inserting solutions.

  • data (dict) – Dict mapping from field names like solution and objective to arrays with data for the solutions. Rankers at least assume the presence of the solution key.

  • add_info (dict) – 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.

Return type

tuple(numpy.ndarray, numpy.ndarray)

reset(emitter, archive)[source]

Resets the internal state of the ranker.

Parameters