Class: Nsga2

Inherits:
AlgorithmBase show all
Includes:
Breed, PhenotypicTruncation
Defined in:
../algorithm/nsga2.rb

Instance Attribute Summary (collapse)

Attributes included from PhenotypicTruncation

#duplicate_elimination

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?, #teardown

Instance Attribute Details

- (Object) inject

Returns the value of attribute inject 



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# File '../algorithm/nsga2.rb', line 83

def inject
  @inject
end

- (Object) shorten_individual

Returns the value of attribute shorten_individual 



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# File '../algorithm/nsga2.rb', line 83

def shorten_individual
  @shorten_individual
end

Instance Method Details

- (Object) setup(config) 



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# File '../algorithm/nsga2.rb', line 69

def setup config
  super

  @selection = Nsga2BinaryTournament.new

  @dom_sort = Dominance.new
  @dom_sort.at_least = @population_size

  @population = load_or_init( @store, @population_size )

  @report.next    
  return @report 
end

- (Object) step 



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# File '../algorithm/nsga2.rb', line 85

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

  depth = 0
  parent_population = []
  front_report = []
  Nsga2Individual.uniq_clear
  @dom_sort.layers( @population ).each do |layer|
    front = Crowding.distance( layer ) { |orig, cdist| Nsga2Individual.new( orig, depth, cdist ) }
    front.each { |individual| individual.cache_uniq }     
    depth += 1
    empty_slots = @population_size - parent_population.size
    front_report << front.size
    if empty_slots >= front.size 
      parent_population.concat front
    else
      front.sort! # { |a,b| b.crowding <=> a.crowding }
      parent_population.concat front[0...empty_slots]
    end
  end

  @report['fronts_sizes'] << front_report.inspect

  @population = parent_population.map do |individual| 
    individual.orig.shorten_chromozome = @shorten_individual
    individual.orig
  end
  
  @report.report @population # reporting
  
  @cross, @injections, @mutate = 0, 0, 0, 0   
  sizes = []

  while @population.size < 2*@population_size 

    @selection.population = parent_population

    new_populaton = breed_by_selector_no_report( @selection, @population_size )
    @population.concat new_populaton

    @population = eliminate_duplicates @population
    sizes << @population.size
   
  end 
 
  @report['eliminated_sizes'] << sizes
  @report['numof_crossovers'] << @cross   
  @report['numof_injections'] << @injections
  @report['numof_mutations'] << @mutate
  @report['time_eval'] << @time_eval      
  @report['numof_evaluations'] << @evaluator.jobs_processed if defined? @evaluator
 
  return @report
end