class NEAT::Evolver::CritterOp

A set of Critter Genotype operators.

Public Class Methods

new(evol) click to toggle source

Calls superclass method

# File lib/rubyneat/evolver.rb, line 254
def initialize(evol)
  super evol.controller
  @evolver = evol
  @npop = evol.npop
end

Public Instance Methods

add_gene!(crit) click to toggle source

Add a gene to the genome¶ ↑

Unlike adding a new neuron, adding a new gene
could result in a circular dependency. If so,
and if recurrency is switched off, we must detect
this condition and switch off the offending neurons.

Obviously, this might result in a loss of functionality, but
oh well.

An easy and obvious check is to make sure we don't
accept any inputs from output neurons, and we don't
do any outputs to input neurons.

Constructs for handling recurrency are present in Expressor.

# File lib/rubyneat/evolver.rb, line 290
def add_gene!(crit)
  n1 = crit.genotype.neurons.values.sample # input
  n2 = crit.genotype.neurons.values.sample # output

  # Sanity checks!
  unless n1 == n2 or n1.output? or n2.input?
    gene = Critter::Genotype::Gene[crit.genotype, n1.name, n2.name, NEAT::controller.gaussian]
    crit.genotype.add_genes gene
    log.debug "add_gene! Added gene #{gene}(#{n1.name} -> #{n2.name}) to #{crit}"
  end
end

add_neuron!(crit) click to toggle source

Add a neuron to given critter¶ ↑

Here, we add a neuron by randomly picking a
gene, and split it into two genes with an intervening
neuron. The old gene is not replaced, but disabled. 2 new genes are
created along with the new neuron.

# File lib/rubyneat/evolver.rb, line 265
def add_neuron!(crit)
  gene = crit.genotype.genes.values.sample
  neu = controller.neural_hidden.values.sample.new(controller)
  g1 = Critter::Genotype::Gene[crit.genotype, gene.in_neuron, neu.name, gene.weight]
  g2 = Critter::Genotype::Gene[crit.genotype, neu.name, gene.out_neuron, gene.weight]
  gene.enabled = false
  crit.genotype.add_neurons neu
  crit.genotype.add_genes g1, g2
  log.debug "add_neuron!: neu #{neu}, g1 #{g1}, g2 #{g2}"
end

disable_gene!(crit) click to toggle source

Pick an enabled gene at random and disable it.

# File lib/rubyneat/evolver.rb, line 303
def disable_gene!(crit)
  gene = crit.genotype.genes.values.reject{|gene| gene.disabled? }.sample
  gene.enabled = false unless gene.nil?
end

reenable_gene!(crit) click to toggle source

Pick a disabled gene at random and reenable it.

# File lib/rubyneat/evolver.rb, line 309
def reenable_gene!(crit)
  gene = crit.genotype.genes.values.reject{|gene| gene.enabled? }.sample
  gene.enabled = true unless gene.nil?
end