pyneat.stagnation module

Track the progress of species and remove those that have stalled.

TODO: Add stagnation tests. TODO: Update module docstrings, and clean up comments and code.

class pyneat.stagnation.Stagnation(config, reporters)

Bases: neat.config.DefaultClassConfig

Track the progress of species and remove those that have stalled.

classmethod parse_config(param_dict)

Parses the stagnation configuration parameters.

Config Parameters:

species_fitness_func (str): The function (mean, max) for

aggregating the fitnesses of the members of each species.

max_stagnation (int): The maximum number of generations a

species can stall for before being deemed stagnant.

species_elitism (int): The minimum number of species that should

be retained.

TODO: Refactor species_elitism as min_species

Parameters:param_dict –

…

Returns:… Return type:DefaultClassConfig

update(species_set, generation)

Required interface method. Updates species fitness history information, checking for ones that have not improved in max_stagnation generations, and - unless it would result in the number of species dropping below the configured species_elitism parameter if they were removed, in which case the highest-fitness species are spared - returns a list with stagnant species marked for removal.

Parameters:

• species_set –

  …

• generation –

  …

Returns:

…

Return type:

list