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Using random.sample for efficiency

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SimpleArt
2020-11-27 22:17:13 -05:00
parent 5407e2ea63
commit d25ea314ac
1 changed files with 32 additions and 29 deletions
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61
src/mutation/mutation_methods.py
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@ -35,29 +35,38 @@ def check_gene_mutation_rate(individual_method):
return new_method return new_method
def loop_selections(population_method): def loop_random_selections(population_method):
"""Runs the population method until enough chromosomes are mutated.""" """Runs the population method until enough chromosomes are mutated.
Provides the indexes of selected chromosomes to mutate using
random.sample to get all indexes fast.
"""
def new_method(ga): def new_method(ga):
sample_space = range(len(ga.population))
sample_size = ceil(len(ga.population)*ga.chromosome_mutation_rate)
# Loop the population method until enough chromosomes are mutated. # Loop the population method until enough chromosomes are mutated.
for _ in range(ceil(len(ga.population)*ga.chromosome_mutation_rate)): for index in random.sample(sample_space, sample_size):
population_method(ga) population_method(ga, index)
return new_method return new_method
def loop_mutations(individual_method): def loop_random_mutations(individual_method):
"""Runs the individual method until enough """Runs the individual method until enough
genes are mutated on the indexed chromosome. genes are mutated on the indexed chromosome.
""" """
# Change input from index to chromosome. # Change input from index to chromosome.
def new_method(ga, index): def new_method(ga, chromosome):
sample_space = range(len(chromosome))
sample_size = ceil(len(chromosome)*ga.gene_mutation_rate)
# Loop the individual method until enough genes are mutated. # Loop the individual method until enough genes are mutated.
for _ in range(ceil(len(ga.population[index])*ga.gene_mutation_rate)): for index in random.sample(sample_space, sample_size):
individual_method(ga, ga.population[index]) individual_method(ga, chromosome, index)
return new_method return new_method
@ -67,44 +76,38 @@ class Mutation_Methods:
# Private method decorators, see above. # Private method decorators, see above.
_check_chromosome_mutation_rate = check_chromosome_mutation_rate _check_chromosome_mutation_rate = check_chromosome_mutation_rate
_check_gene_mutation_rate = check_gene_mutation_rate _check_gene_mutation_rate = check_gene_mutation_rate
_loop_selections = loop_selections _loop_random_selections = loop_random_selections
_loop_mutations = loop_mutations _loop_random_mutations = loop_random_mutations
class Population: class Population:
"""Methods for selecting chromosomes to mutate""" """Methods for selecting chromosomes to mutate"""
@check_chromosome_mutation_rate @check_chromosome_mutation_rate
@loop_selections @loop_random_selections
def random_selection(ga): def random_selection(ga, index):
"""Selects random chromosomes.""" """Selects random chromosomes."""
index = random.randrange(len(ga.population)) ga.mutation_individual_impl(ga, ga.population[index])
ga.mutation_individual_impl(ga, index)
@check_chromosome_mutation_rate @check_chromosome_mutation_rate
@loop_selections @loop_random_selections
def random_avoid_best(ga): def random_avoid_best(ga, index):
"""Selects random chromosomes while avoiding the best chromosomes. (Elitism)""" """Selects random chromosomes while avoiding the best chromosomes. (Elitism)"""
index = random.randrange( if index > ga.percent_converged*len(ga.population)*3/16:
ceil(ga.percent_converged*len(ga.population)*3/16), ga.mutation_individual_impl(ga, ga.population[index])
len(ga.population)
)
ga.mutation_individual_impl(ga, index)
class Individual: class Individual:
"""Methods for mutating a single chromosome.""" """Methods for mutating a single chromosome."""
@check_gene_mutation_rate @check_gene_mutation_rate
@loop_mutations @loop_random_mutations
def individual_genes(ga, chromosome): def individual_genes(ga, chromosome, index):
"""Mutates a random gene in the chromosome.""" """Mutates a random gene in the chromosome."""
index = random.randrange(len(chromosome))
# Using the chromosome_impl # Using the chromosome_impl
if ga.chromosome_impl is not None: if ga.chromosome_impl is not None:
chromosome[index] = ga.make_gene(ga.chromosome_impl()[index]) chromosome[index] = ga.make_gene(ga.chromosome_impl()[index])
@ -123,13 +126,13 @@ class Mutation_Methods:
by changing the order of the genes.""" by changing the order of the genes."""
@check_gene_mutation_rate @check_gene_mutation_rate
@loop_mutations @loop_random_mutations
def swap_genes(ga, chromosome): def swap_genes(ga, chromosome, index):
"""Swaps two random genes in the chromosome.""" """Swaps two random genes in the chromosome."""
# Indexes of genes to swap # Indexes of genes to swap
index_one = random.randrange(len(chromosome)) index_one = index
index_two = random.randrange(len(chromosome)) index_two = random.randrange(index_one)
# Swap genes # Swap genes
chromosome[index_one], chromosome[index_two] = chromosome[index_two], chromosome[index_one] chromosome[index_one], chromosome[index_two] = chromosome[index_two], chromosome[index_one]