Class: EvoSynth::Population

Inherits:
ArrayGenome show all
Defined in:
lib/evosynth/core/population.rb

Overview

This class is used to create and maintain a population. In this case a population is simply a Array of individuals that keeps track of changes.

Constant Summary

Constants inherited from ArrayGenome

ArrayGenome::METHODS_THAT_CHANGE_ARRAY

Instance Method Summary collapse

Methods inherited from ArrayGenome

#changed=, #changed?, #clone

Constructor Details

#initialize(*args) ⇒ Population

:call-seq: Population.new -> Population Population.new(size) -> Population (with given size) Population.new(size) { block } -> Population (with given size and block to intialize each individual)

Creates a population



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# File 'lib/evosynth/core/population.rb', line 39

def initialize(*args)
	super(*args)
	self.map! { |individual| yield } if block_given?
end

Instance Method Details

#add(individual) ⇒ Object

Adds a individual to the population.



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# File 'lib/evosynth/core/population.rb', line 54

def add(individual)
	self << individual
end

#best(count = 1) ⇒ Object

:call-seq: p = Population.new p.best #=> Returns the best individual p.best(3) #=> Returns the 3 best individuals

Returns the best N individuals (by comparing with <=>) of the population.



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# File 'lib/evosynth/core/population.rb', line 83

def best(count = 1)
	self.sort! if self.changed?
	self.changed = false
	count == 1 ? self.last : self.last(count).reverse
end

#deep_clone ⇒ Object

Returns a clone of the population (deep_clone)



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# File 'lib/evosynth/core/population.rb', line 46

def deep_clone
	my_clone = self.clone
	self.each_index { |index| my_clone[index] = self[index].deep_clone }
	my_clone
end

#remove(individual) ⇒ Object

Removes a give individual (first occurence) from the population.



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# File 'lib/evosynth/core/population.rb', line 60

def remove(individual)
	# FIXME: this is a rather ugly hack
	# -> should be replaced with a cool 1.9 function

	found = nil
	self.each_index do |index|
		if self[index] == individual
			found = index
			break
		end
	end

	self.delete_at(found) if found != nil
end

#to_s ⇒ Object

:call-seq: to_s -> string

Returns description of this individual

p = Population.new p.to_s #=> “Population <size=0>”



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# File 'lib/evosynth/core/population.rb', line 110

def to_s
	begin
		"Population <size=#{self.size}, best.fitness=#{best.fitness}, worst.fitness=#{worst.fitness}>"
	rescue
		"Population <size=#{self.size}>"
	end
end

#worst(count = 1) ⇒ Object

:call-seq: p = Population.new p.worst #=> Returns the worst individual p.worst(3) #=> Returns the 3 worst individuals

Returns the worst N individuals (by comparing with <=>) of the population.



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# File 'lib/evosynth/core/population.rb', line 96

def worst(count = 1)
	self.sort! if self.changed?
	self.changed = false
	count == 1 ? self.first : self.first(count).reverse
end