Selection

• Base_selections
  • Probabilistic_tournament_selection
  • Relative_weighted_selection
  • Simple_tournament_selection
  • Truncation_selection
  • Weighted_selection

Selection

class gaggle.operators.selection.selection.Selection(ga_args: GAArgs = None)

Bases: object

The parent class for any Selection Operator. It gives functions to select the protected (elitism) set and to select the parents for crossover.

select_all(manager: PopulationManager, mates_per_crossover: int, children_per_crossover: int) → PopulationManager

Calls both the protoected and parent selection fucntions

abstract select_parents(manager: PopulationManager, mates_per_crossover: int, children_per_crossover: int) → PopulationManager

Should select both the parents and the mating tuples

select_protected(manager: PopulationManager) → PopulationManager

By default, the select protected is elitism, to turn off elitism, set elitism to 0. in ga_args.

Selection_factory

class gaggle.operators.selection.selection_factory.SelectionFactory

Bases: object

Factory that generates pre-existing available selection operators. SelectionFactory.selections stores said selection operators as a dictionary with their name as the key and the uninitialized selection object as the value.

classmethod from_ga_args(ga_args: GAArgs = None) → Selection

Initializes the requested selection from the dictionary of available selections.

This is done by using the attribute ga_args.selection as the lookup key to SelectionFactory.selections.

Parameters:

ga_args – GAArgs object for the current run

Returns:

An initialized selection class object.

classmethod get_keys()

Returns the list of currently registered selections

selections = {'probabilistic_tournament': <class 'gaggle.operators.selection.base_selections.probabilistic_tournament_selection.ProbabilisticTournamentSelection'>, 'relative_weighted': <class 'gaggle.operators.selection.base_selections.relative_weighted_selection.RelativeWeightedSelection'>, 'simple_tournament': <class 'gaggle.operators.selection.base_selections.simple_tournament_selection.SimpleTournamentSelection'>, 'truncation': <class 'gaggle.operators.selection.base_selections.truncation_selection.TruncationSelection'>, 'weighted': <class 'gaggle.operators.selection.base_selections.weighted_selection.WeightedSelection'>}

classmethod update(key, selection)

Add a new selection operator to the dictionary of selections that can be created.

It is added to SelectionFactory.selections

Parameters:

• key – selection name that will be used as the dictionary lookup key

• selection – selection class object, it needs to not be already initialized