Class: ParetoGPSimplified

Inherits:
AlgorithmBase show all
Includes:
PhenotypicTruncation
Defined in:
../algorithm/paretogp_simplified.rb

Instance Attribute Summary (collapse)

Attributes included from PhenotypicTruncation

#duplicate_elimination, #shorten_individual

Attributes inherited from AlgorithmBase

#init, #population_size, #probabilities, #termination

Instance Method Summary (collapse)

Methods included from PhenotypicTruncation

#eliminate_duplicates, #phenotypic_truncation

Methods inherited from AlgorithmBase

#finished?

Instance Attribute Details

- (Object) archive_size

Returns the value of attribute archive_size 



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# File '../algorithm/paretogp_simplified.rb', line 8

def archive_size
  @archive_size
end

- (Object) generations_per_cascade

Returns the value of attribute generations_per_cascade 



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# File '../algorithm/paretogp_simplified.rb', line 8

def generations_per_cascade
  @generations_per_cascade
end

- (Object) mutation_probability

Returns the value of attribute mutation_probability 



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# File '../algorithm/paretogp_simplified.rb', line 8

def mutation_probability
  @mutation_probability
end

- (Object) tournament_size

Returns the value of attribute tournament_size 



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# File '../algorithm/paretogp_simplified.rb', line 8

def tournament_size
  @tournament_size
end

Instance Method Details

- (Object) setup(config) 



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# File '../algorithm/paretogp_simplified.rb', line 10

def setup config
  super

  @population_tourney = ParetoTourney.new 
  @population_tourney.tournament_size = @tournament_size

  @population = []

  @archive = load_or_init( @store, @archive_size )
 
  @steps = 0
  @generation = 0
  return @report       
end

- (Object) step 



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# File '../algorithm/paretogp_simplified.rb', line 31

def step
  @report.next       
  @report << "--------- step #{@steps += 1}, generation #{@generation}" 

   # init population   
  if @generation == 0
    @report << "initializing population"  
    @population = []
    init_population( @population, @population_size )   
  end

  # create a new population from the current one
  population_pipe = []
  archive_pipe = []
  new_population = [] 
  while new_population.size < @population_size

    population_pipe = @population_tourney.select_front @population while population_pipe.empty?
    archive_pipe = Util.permutate @archive while archive_pipe.empty?

    parent1, parent2 = [ population_pipe.shift, archive_pipe.shift ]
    chromozome1, chromozome2 = @crossover.crossover( parent1.genotype, parent2.genotype, parent1.track_support, parent2.track_support )     

    individual = @cfg.factory( 'individual', @mapper, chromozome1 )
    if individual.valid? and rand < @mutation_probability      
      chromozome1 = @mutation.mutation( chromozome1, individual.track_support )
      individual = @cfg.factory( 'individual', @mapper, chromozome1 ) 
    end
      
    new_population << individual if individual.valid?

    individual = @cfg.factory( 'individual', @mapper, chromozome2 ) 
    new_population << individual if individual.valid?
     
  end

  @evaluator.run new_population if defined? @evaluator

  @population = new_population
 
  # keep population extremes
  @population.first.objective_symbols.each do |obj|
    best = Pareto.objective_best( @population, @population.first.class, obj )
    @archive.push best
    @report['pop_best_' + obj.to_s] << best.send(obj)
  end

  if @generation == @generations_per_cascade 

    # archive merging     
    @archive = phenotypic_truncation( Pareto.nondominated( @archive ), @archive_size )

    @report.report @archive      
    @generation = 0
  else
    @generation += 1
  end # consolidation

  return @report 
end

- (Object) teardown 



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# File '../algorithm/paretogp_simplified.rb', line 25

def teardown
  @report << "--------- finished:"
  @store.save @archive
  return @report   
end