Class: Selection::Roulette

Inherits:

Object

• Object
• Selection::Roulette

show all

Includes:

SelectMore

Defined in:

../lib/roulette.rb

Overview

Defined Under Namespace

Classes: Slot

Instance Attribute Summary (collapse)

• - (Object) population

  The population to select from.

• - (Object) proportional_by

  The symbol for obtaining the proportion of an individual.

• - (Object) random

  The source of randomness, used for calling “random.rand( limit )”, defaulting to ‘Kernel’ class.

Attributes included from SelectMore

#unique_winners

Instance Method Summary (collapse)

• - (Roulette) initialize(proportional_by = nil, &block) constructor

  Set the proportional_by or the block for obtaining invividual’s proportion.

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

  Select one individual from the population.

Methods included from SelectMore

#select

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# File '../lib/roulette.rb', line 17

def initialize proportional_by=nil, &block
  @prop = if proportional_by.nil?
            block
          else
            proc { |individual| individual.send(proportional_by) }
          end
  @proportional_by = proportional_by     
  @random = Kernel
  @population = nil 
  @wheel = nil
end

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# File '../lib/roulette.rb', line 33

def population
  @population
end

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# File '../lib/roulette.rb', line 37

def proportional_by
  @proportional_by
end

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

def random
  @random
end

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# File '../lib/roulette.rb', line 40

def select_one population=self.population 
  @sum,@wheel = wheel_core population 
  @population = population
  select_one_internal
end