Class: EvoSynth::Mutations::GaussMutation

Inherits:
Object
  • Object
show all
Defined in:
lib/evosynth/operators/mutations/gauss_mutation.rb

Overview

GAUSS-MUTATION (Weicker page 60)

TODO: needs rdoc

Constant Summary collapse

DEFAULT_SIGMA = 
1.0
DEFAULT_LOWER_BOUND = 
-1 * Float::MAX
DEFAULT_UPPER_BOUND = 
Float::MAX

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sigma = DEFAULT_SIGMA, lower_bound = DEFAULT_LOWER_BOUND, upper_bound = DEFAULT_UPPER_BOUND) ⇒ GaussMutation

Returns a new instance of GaussMutation.


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# File 'lib/evosynth/operators/mutations/gauss_mutation.rb', line 39

def initialize(sigma = DEFAULT_SIGMA, lower_bound = DEFAULT_LOWER_BOUND, upper_bound = DEFAULT_UPPER_BOUND)
	@sigma = sigma
	@lower_bound = lower_bound
	@upper_bound = upper_bound
end

Instance Attribute Details

#lower_bound ⇒ Object

Returns the value of attribute lower_bound.


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# File 'lib/evosynth/operators/mutations/gauss_mutation.rb', line 33

def lower_bound
  @lower_bound
end

#sigma ⇒ Object

Returns the value of attribute sigma.


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# File 'lib/evosynth/operators/mutations/gauss_mutation.rb', line 33

def sigma
  @sigma
end

#upper_bound ⇒ Object

Returns the value of attribute upper_bound.


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# File 'lib/evosynth/operators/mutations/gauss_mutation.rb', line 33

def upper_bound
  @upper_bound
end

Instance Method Details

#mutate(individual) ⇒ Object 


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# File 'lib/evosynth/operators/mutations/gauss_mutation.rb', line 45

def mutate(individual)
	mutated = individual.deep_clone

	mutated.genome.map! do |gene|
		gene += EvoSynth.nrand(0.0, @sigma)
		gene = @lower_bound if gene < @lower_bound
		gene = @upper_bound if gene > @upper_bound
		gene
	end

	mutated
end

#to_s ⇒ Object 


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# File 'lib/evosynth/operators/mutations/gauss_mutation.rb', line 58

def to_s
	"gauss mutation <sigma: #{@sigma}, lower bound: #{@lower_bound}, upper_bound: #{@upper_bound}>"
end