Class: EvoSynth::Evolvers::AdaptiveES

Inherits:
Object
  • Object
show all
Includes:
Evolver
Defined in:
lib/evosynth/evolvers/evolution_strategies/adaptive_es.rb

Overview

ES-ADAPTIV (Weicker Page 135)

TODO: rdoc (mutation and adjustment are fixed!)

Constant Summary collapse

DEFAULT_SIGMA = 
0.1
DEFAULT_CHILD_FACTOR = 
5
DEFAULT_MODIFICATION_FREQUENCY = 
10
DEFAULT_MUTATION = 
EvoSynth::Mutations::GaussMutation.new(DEFAULT_SIGMA)
DEFAULT_PARENT_SELECTION = 
EvoSynth::Selections::RandomSelection.new
DEFAULT_ENV_SELECTION = 
EvoSynth::Selections::SelectBest.new
DEFAULT_ADJUSTMENT = 
EvoSynth::Adjustments::AdaptiveAdjustment.new

Instance Attribute Summary collapse

Attributes included from RunnableEvolver

#generations_computed

Instance Method Summary collapse

Methods included from ProfileUsingEvolver

#init_profile, #use_profile

Methods included from RunnableEvolver

#run_until, #run_until_fitness_reached, #run_until_generations_reached

Constructor Details

#initialize(profile) ⇒ AdaptiveES

Returns a new instance of AdaptiveES.



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# File 'lib/evosynth/evolvers/evolution_strategies/adaptive_es.rb', line 48

def initialize(profile)
	init_profile :population,
	    :evaluator,
		:sigma					=> DEFAULT_SIGMA,
	    :child_factor			=> DEFAULT_CHILD_FACTOR,
	    :modification_frequency => DEFAULT_MODIFICATION_FREQUENCY,
	    :enviromental_selection => DEFAULT_ENV_SELECTION,
	    :parent_selection		=> DEFAULT_PARENT_SELECTION

	use_profile profile
	@adjustment = DEFAULT_ADJUSTMENT
	@mutation = DEFAULT_MUTATION
	@success = 0

	@population.each { |individual| @evaluator.calculate_and_set_initial_fitness(individual) }
end

Instance Attribute Details

#success ⇒ Object (readonly)

Returns the value of attribute success.



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# File 'lib/evosynth/evolvers/evolution_strategies/adaptive_es.rb', line 38

def success
  @success
end

Instance Method Details

#best_solution ⇒ Object 



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# File 'lib/evosynth/evolvers/evolution_strategies/adaptive_es.rb', line 69

def best_solution
	@population.best
end

#next_generation ⇒ Object 



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# File 'lib/evosynth/evolvers/evolution_strategies/adaptive_es.rb', line 81

def next_generation
	child_population = EvoSynth::Population.new

	(@child_factor * @population.size).times do
		parent = @parent_selection.select(@population, 1).first
		@mutation.sigma = @sigma
		child = @mutation.mutate(parent)
 
		@evaluator.calculate_and_set_fitness(child)
		@success += 1 if child > parent
		child_population << child
	end

	@population = @enviromental_selection.select(child_population, @population.size)
	if @generations_computed % @modification_frequency == 0
		success_rate =  @success / (@modification_frequency - (@child_factor * @population.size))
		@sigma = @adjustment.adjust(@sigma, success_rate)
		@success = 0
	end
end

#return_result ⇒ Object 



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# File 'lib/evosynth/evolvers/evolution_strategies/adaptive_es.rb', line 77

def return_result
	@population
end

#to_s ⇒ Object 



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# File 'lib/evosynth/evolvers/evolution_strategies/adaptive_es.rb', line 65

def to_s
	"adaptive ES <sigma: #{@sigma}, success: #{@success}, mutation: #{@mutation}, parent selection: #{@parent_selection}, enviromental selection: #{@enviromental_selection}>"
end

#worst_solution ⇒ Object 



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# File 'lib/evosynth/evolvers/evolution_strategies/adaptive_es.rb', line 73

def worst_solution
	@population.worst
end