Class: Selection::RankRoulette

Inherits:

Object

• Object
• Selection::RankRoulette

show all

Includes:

SelectMore

Defined in:

../lib/rank_roulette.rb

Overview

Instance Attribute Summary (collapse)

• - (Object) population

  The population to select from.

Attributes included from SelectMore

#unique_winners

Instance Method Summary (collapse)

• - (RankRoulette) initialize(ranker) constructor

  Set the instance of the Ranking object which will be used for ranking the population before the selection.

• - (Object) random=(rnd)

  Set the source of randomness for the roulette, using Roulette#random=.

• - (Object) select_one(population = self.population)

  Rank the population and then select one individual from it.

Methods included from SelectMore

#select

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# File '../lib/rank_roulette.rb', line 18

def initialize ranker
  raise "RankRoulette: invalid Ranking object" unless ranker.kind_of? Ranking     
  @ranker = ranker
  @roulette = Roulette.new :proportion
  @population = nil     
  @ranked = nil
end

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# File '../lib/rank_roulette.rb', line 27

def population
  @population
end

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# File '../lib/rank_roulette.rb', line 30

def random= rnd
  @roulette.random = rnd
end

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# File '../lib/rank_roulette.rb', line 36

def select_one population=self.population
  @ranked = @ranker.rank( population ) 
  @population = population

  select_one_internal
end