Class: EvoSynth::Mutations::ExchangeMutation

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

Constant Summary collapse

DEFAULT_SWAP_COUNT = 
2

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(swap_count = DEFAULT_SWAP_COUNT) ⇒ ExchangeMutation

:call-seq: ExchangeMutation.new ExchangeMutation(Fixnum) -> ExchangeMutation (overrides default swap count)

Returns a new ExchangeMutation. In the first form, the default swap count is used. In the second it creates a ExchangeMutation with the given swap count.

ExchangeMutation.new
ExchangeMutation.new(3)



52
53
54
 
# File 'lib/evosynth/operators/mutations/exchange_mutation.rb', line 52

def initialize(swap_count = DEFAULT_SWAP_COUNT)
  @swap_count = swap_count
end

Instance Attribute Details

#swap_count ⇒ Object

The number of genes that will be swapped during this mutation (default is 2).



38
39
40
 
# File 'lib/evosynth/operators/mutations/exchange_mutation.rb', line 38

def swap_count
  @swap_count
end

Instance Method Details

#mutate(individual) ⇒ Object

:call-seq: mutate(Individual) -> Individual

Returns the mutation of a given individual.

m = ExchangeMutation.new
m.mutate(a_individual)   #=> a_new_individual



64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
 
# File 'lib/evosynth/operators/mutations/exchange_mutation.rb', line 64

def mutate(individual)
  mutated = individual.deep_clone
  genome = mutated.genome

  indexes = rand_indexes(genome.size)

  (indexes.size - 1).times do |index|
    index_one = indexes[index]
    index_two = indexes[index + 1]
    index_two = indexes[0] if index_two.nil?

    genome[index_one], genome[index_two] = genome[index_two], genome[index_one]
  end

  mutated
end

#to_s ⇒ Object

:call-seq: to_s -> string

Returns description of this mutation

m = ExchangeMutation.new
m.to_s                   #=> "exchange mutation"



89
90
91
 
# File 'lib/evosynth/operators/mutations/exchange_mutation.rb', line 89

def to_s
  "exchange mutation <swap count: #{@swap_count}>"
end