Class: GeneticAlgorithms::Engine

Inherits:
Object
  • Object
show all
Defined in:
lib/genetic_algorithms/engine.rb

Class Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Engine 



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# File 'lib/genetic_algorithms/engine.rb', line 16

def initialize
  Engine.configure
  chromosomes = Population.random_chromosomes Engine.population_size, Engine.chromosome_length
  @population = Population.new chromosomes
end

Class Attribute Details

.chromosome_length ⇒ Object

Returns the value of attribute chromosome_length.



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# File 'lib/genetic_algorithms/engine.rb', line 5

def chromosome_length
  @chromosome_length
end

.num_generations ⇒ Object

Returns the value of attribute num_generations.



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# File 'lib/genetic_algorithms/engine.rb', line 5

def num_generations
  @num_generations
end

.population_size ⇒ Object

Returns the value of attribute population_size.



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# File 'lib/genetic_algorithms/engine.rb', line 5

def population_size
  @population_size
end

Class Method Details

.configure(&block) ⇒ Object 



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# File 'lib/genetic_algorithms/engine.rb', line 8

def self.configure(&block)
  block.call(self) if block_given?

  Engine.population_size    = 10  unless Engine.population_size
  Engine.chromosome_length  = 10  unless Engine.chromosome_length
  Engine.num_generations    = 5   unless Engine.num_generations
end

Instance Method Details

#start(best_possible_score, &fitness_function) ⇒ Object 



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# File 'lib/genetic_algorithms/engine.rb', line 22

def start(best_possible_score, &fitness_function)
  highest_score, best_gen = 0, nil
  
  (0...Engine.num_generations).inject(@population) do |newest_population, i|
    next_gen = newest_population.evolve(&fitness_function)

    if newest_population.highest_score > highest_score
      highest_score, best_gen = newest_population.highest_score, newest_population
      break if highest_score == best_possible_score
    end

    next_gen
  end

  {best_gen.best_solution => best_gen.highest_score}
end