Class: PetriDish::World

Inherits:
Object
  • Object
show all
Defined in:
lib/petri_dish/world.rb

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.configuration ⇒ Object (readonly)

Returns the value of attribute configuration.



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# File 'lib/petri_dish/world.rb', line 16

def configuration
  @configuration
end

.end_condition_reached ⇒ Object (readonly)

Returns the value of attribute end_condition_reached.



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# File 'lib/petri_dish/world.rb', line 16

def end_condition_reached
  @end_condition_reached
end

.metadata ⇒ Object

Returns the value of attribute metadata.



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# File 'lib/petri_dish/world.rb', line 15

def metadata
  @metadata
end

Class Method Details

.run(members:, configuration: Configuration.new, metadata: Metadata.new) ⇒ Object 



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# File 'lib/petri_dish/world.rb', line 18

def run(
  members:,
  configuration: Configuration.new,
  metadata: Metadata.new
)
  configuration.generation_start_callback&.call(metadata.generation_count)

  end_condition_reached = false
  max_generation_reached = false

  if metadata.generation_count.zero?
    configuration.logger.info "Run started."
    metadata.start
  end

  configuration.logger.info(metadata.to_json)

  if metadata.generation_count >= configuration.max_generations
    configuration.max_generation_reached_callback&.call
    max_generation_reached = true
  end

  elitism_count = (configuration.population_size * configuration.elitism_rate).round
  elite_members = members.sort_by(&:fitness).last(elitism_count)

  new_members = (configuration.population_size - elitism_count).times.map do
    child_member = configuration.crossover_function.call(configuration.parents_selection_function.call(members))

    configuration.mutation_function.call(child_member).tap do |mutated_child|
      if metadata.highest_fitness < mutated_child.fitness
        metadata.set_highest_fitness(mutated_child.fitness)
        configuration.highest_fitness_callback&.call(mutated_child)

        configuration.logger.info(metadata.to_json)
      end

      if configuration.end_condition_function.call(mutated_child)
        configuration.end_condition_reached_callback&.call(mutated_child)
        end_condition_reached = true
      end
    end
  end

  metadata.increment_generation
  run(members: (new_members + elite_members), configuration: configuration, metadata: metadata) unless end_condition_reached || max_generation_reached
end