Test Implementation for selection/crossover/mutation

The current test implementation includes random mutation, single point crossover, and tournament selection. The implementation, in short, is a nested approach. The selection method is the only thing actually called by the GA. Both crossover and mutation occur within the selection method. As long as these three systems all follow a standard input/output system, any implementation we build, as well as any user implementations, will work perfectly. The selection function must take GA as a parameter and output a new population. Crossover takes in GA and outputs a population. Mutation takes a chromosome set and outputs a new chromosome set.

Many of the changes in this commit are regarding this test implementation. I have also changed many of the file names from "x_examples" to "x_types" and updated the class names to follow capitalziation standards. I did this because I feel personally like the built-in mutation, crossover, and selection implementations are less "examples" and more just already built implementations to make the code required from the user smaller.
This commit is contained in:
Ryley
2020-10-04 08:00:33 -04:00
parent 6aec9770b6
commit 7e587d48d0
17 changed files with 364 additions and 1 deletions

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@ -1,3 +1,4 @@
<<<<<<< Updated upstream
# Import all the data prebuilt modules # Import all the data prebuilt modules
from initialization.population_structure.population import population as create_population from initialization.population_structure.population import population as create_population
from initialization.chromosome_structure.chromosome import chromosome as create_chromosome from initialization.chromosome_structure.chromosome import chromosome as create_chromosome
@ -107,6 +108,90 @@ class GA:
# If you want to evolve through a number of generations # If you want to evolve through a number of generations
# and be able to pause and output data based on that generation run. # and be able to pause and output data based on that generation run.
pass pass
=======
import random
# Import all the data structure prebuilt modules
from initialization import Population as create_population
from initialization import Chromosome as create_chromosome
from initialization import Gene as create_gene
# Import example classes
from fitness_function import Fitness_Examples
from initialization import Initialization_Types
from termination_point import Termination_Types
from selection import Selection_Types
from crossover import Crossover_Types
from mutation import Mutation_Types
class GA:
def __init__(self):
"""Initialize the GA."""
# Initilization variables
self.chromosome_length = 10
self.population_size = 100
self.chromosome_impl = None
self.gene_impl = None
self.population = None
# Termination varibles
self.current_generation = 0
self.current_fitness = 0
self.generation_goal = 35
self.fitness_goal = 3
# Mutation variables
self.mutation_rate = 0.075
# Rerun already computed fitness
self.update_fitness = True
# Defualt EastGA implimentation structure
self.initialization_impl = Initialization_Types().random_initialization
self.fitness_function_impl = Fitness_Examples().is_it_5
self.mutation_impl = Mutation_Types().random_mutation
self.selection_impl = Selection_Types().tournament_selection
self.crossover_impl = Crossover_Types().single_point_crossover
self.termination_impl = Termination_Types().generation_based
def initialize_population(self):
"""Initialize the population using the initialization
implimentation that is currently set"""
self.population = self.initialization_impl(self)
def set_all_fitness(self,chromosome_set):
"""Will get and set the fitness of each chromosome in the population.
If update_fitness is set then all fitness values are updated.
Otherwise only fitness values set to None (i.e. uninitialized
fitness values) are updated."""
# Get each chromosome in the population
for chromosome in chromosome_set:
if(chromosome.fitness == None or self.update_fitness == True):
# Set the chromosomes fitness using the fitness function
chromosome.set_fitness(self.fitness_function_impl(chromosome))
def evolve(self):
"""Runs the ga until the termination point has been satisfied."""
# While the termination point hasnt been reached keep running
while(self.active()):
self.evolve_generation()
def evolve_generation(self, number_of_generations = 1, consider_termination = True):
"""Evolves the ga the specified number of generations."""
while(number_of_generations > 0 and (consider_termination == False or self.termination_impl(self))):
# If its the first generation then initialize the population
if self.current_generation == 0:
self.initialize_population()
self.set_all_fitness(self.population.chromosomes)
next_population = self.selection_impl(self)
self.population = next_population
self.set_all_fitness(self.population.chromosomes)
number_of_generations -= 1
self.current_generation += 1
>>>>>>> Stashed changes
def active(self):
"""Returns if the ga should terminate base on the termination implimented"""
return self.termination_impl(self)
def make_gene(self,value): def make_gene(self,value):
return create_gene(value) return create_gene(value)

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@ -0,0 +1,2 @@
# FROM (. means local) file_name IMPORT function_name
from .crossover_types import Crossover_Types

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@ -0,0 +1,39 @@
import random
from initialization.chromosome_structure.chromosome import Chromosome
from initialization.population_structure.population import Population
class Crossover_Types:
""" Crossover explination goes here.
Points - Defined as sections between the chromosomes genetic makeup
"""
def __init__(self):
pass
def single_point_crossover(self, ga):
"""Single point crossover is when a "point" is selected and the genetic
make up of the two parent chromosomes are "Crossed" or better known as swapped"""
crossover_pool = []
for i in range(ga.population_size):
if ga.population.get_all_chromosomes()[i].selected:
crossover_pool.append(ga.population.get_all_chromosomes()[i])
new_population = Population()
for i in range(len(crossover_pool)):
if i + 1 < len(crossover_pool):
new_gene_set = []
parent_one = crossover_pool[i].get_genes()
parent_two = crossover_pool[i+1].get_genes()
halfway_point = int(ga.chromosome_length/2)
new_gene_set.extend(parent_one[0:halfway_point])
new_gene_set.extend(parent_two[halfway_point:])
new_chromosome = Chromosome(new_gene_set)
new_population.add_chromosome(new_chromosome)
return new_population
def multi_point_crossover(self, ga,number_of_points = 2):
"""Multi point crossover is when a specific number (More then one) of
"points" are created to merge the genetic makup of the chromosomes."""
pass

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@ -0,0 +1,2 @@
# FROM (. means local) file_name IMPORT class name
from .examples import Fitness_Examples

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@ -0,0 +1,17 @@
class Fitness_Examples:
"""Fitness function examples used"""
def is_it_5(self, chromosome):
"""A very simple case test function - If the chromosomes gene value is a 5 add one
to the chromosomes overall fitness value."""
# Overall fitness value
fitness = 0
# For each gene in the chromosome
for gene in chromosome.genes:
# Check if its value = 5
if(gene.value == 5):
# If its value is 5 then add one to
# the overal fitness of the chromosome.
fitness += 1
return fitness

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@ -0,0 +1,5 @@
# FROM (. means local) file_name IMPORT function_name
from .initialization_types import Initialization_Types
from .population_structure.population import Population
from .chromosome_structure.chromosome import Chromosome
from .gene_structure.gene import Gene

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@ -1,6 +1,11 @@
<<<<<<< Updated upstream
class chromosome: class chromosome:
# fitness = Empty; genes = [gene, gene, gene, etc.] # fitness = Empty; genes = [gene, gene, gene, etc.]
=======
class Chromosome:
>>>>>>> Stashed changes
def __init__(self, genes = None): def __init__(self, genes = None):
if genes is None: if genes is None:
self.genes = [] self.genes = []

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@ -3,7 +3,12 @@ def check_gene(value):
assert value != "" , "Gene can not be empty" assert value != "" , "Gene can not be empty"
return value return value
<<<<<<< Updated upstream
class gene: class gene:
=======
class Gene:
>>>>>>> Stashed changes
def __init__(self, value): def __init__(self, value):
self.fitness = None self.fitness = None
self.value = check_gene(value) self.value = check_gene(value)
@ -17,7 +22,12 @@ class gene:
def set_fitness(self, fitness): def set_fitness(self, fitness):
self.fitness = fitness self.fitness = fitness
<<<<<<< Updated upstream
def set_value(self): def set_value(self):
=======
def set_value(self, value):
"""Set value of the gene"""
>>>>>>> Stashed changes
self.value = value self.value = value
def __repr__(self): def __repr__(self):

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@ -0,0 +1,32 @@
# Import the data structure
from .population_structure.population import Population as create_population
from .chromosome_structure.chromosome import Chromosome as create_chromosome
from .gene_structure.gene import Gene as create_gene
class Initialization_Types:
"""Initialization examples that are used as defaults and examples"""
def random_initialization(self, ga):
"""Takes the initialization inputs and choregraphs them to output the type of population
with the given parameters."""
# Create the population object
population = create_population()
# Fill the population with chromosomes
for i in range(ga.population_size):
chromosome = create_chromosome()
#Fill the Chromosome with genes
for j in range(ga.chromosome_length):
# Using the chromosome_impl to set every index inside of the chromosome
if ga.chromosome_impl != None:
# Each chromosome location is specified with its own function
chromosome.add_gene(create_gene(ga.chromosome_impl(j)))
# Will break if chromosome_length != len(lists) in domain
elif ga.gene_impl != None:
function = ga.gene_impl[0]
chromosome.add_gene(create_gene(function(*ga.gene_impl[1:])))
else:
#Exit because either were not specified
print("You did not specify any initialization constraints.")
population.add_chromosome(chromosome)
return population

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@ -1,4 +1,4 @@
class population: class Population:
# fitness = Empty; population = [chromosome, chromosome, etc.] # fitness = Empty; population = [chromosome, chromosome, etc.]
def __init__(self, chromosomes = None): def __init__(self, chromosomes = None):
@ -21,7 +21,12 @@ class population:
del self.chromosomes[index] del self.chromosomes[index]
def get_all_chromosomes(self): def get_all_chromosomes(self):
<<<<<<< Updated upstream
return chromosomes return chromosomes
=======
"""returns all chromosomes in the population"""
return self.chromosomes
>>>>>>> Stashed changes
def get_fitness(self): def get_fitness(self):
return self.fitness return self.fitness

2
src/mutation/__init__.py Normal file
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@ -0,0 +1,2 @@
# FROM (. means local) file_name IMPORT function_name
from .mutation_types import Mutation_Types

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@ -0,0 +1,21 @@
import random
class Mutation_Types:
def __init__(self):
pass
def random_mutation(self, ga, chromosome_set = None):
if chromosome_set == None:
chromosome_set = ga.population
chromosome_mutate_num = int(len(chromosome_set)*ga.mutation_rate)
temp_population = ga.initialization_impl(ga)
while chromosome_mutate_num > 0:
chromosome_set[random.randint(0,ga.population_size-1)] = temp_population.get_all_chromosomes()[chromosome_mutate_num]
chromosome_mutate_num -= 1
return chromosome_set

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@ -1,8 +1,14 @@
import EasyGA import EasyGA
<<<<<<< Updated upstream
=======
import random
>>>>>>> Stashed changes
# Create the Genetic algorithm # Create the Genetic algorithm
ga = EasyGA.GA() ga = EasyGA.GA()
<<<<<<< Updated upstream
#Creating a gene with no fitness #Creating a gene with no fitness
gene1 = ga.make_gene("Im a gene") gene1 = ga.make_gene("Im a gene")
gene2 = ga.make_gene("Im also a gene") gene2 = ga.make_gene("Im also a gene")
@ -18,3 +24,12 @@ print(gene1)
print(chromosome) print(chromosome)
print(populaiton) print(populaiton)
populaiton.print_all() populaiton.print_all()
=======
ga.gene_impl = [random.randrange,1,10]
# Run Everyhting
ga.evolve()
# Print the current population
ga.population.print_all()
>>>>>>> Stashed changes

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@ -0,0 +1,2 @@
# FROM (. means local) file_name IMPORT function_name
from .selection_types import Selection_Types

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@ -0,0 +1,103 @@
import random
from initialization.chromosome_structure.chromosome import Chromosome as create_chromosome
from initialization.gene_structure.gene import Gene as create_gene
from initialization.population_structure.population import Population
from initialization.chromosome_structure.chromosome import Chromosome
class Selection_Types:
"""Selection is the process by which chromosomes are selected for crossover and eventually, influence the next generation of chromosomes."""
def __init__(self):
pass
def tournament_selection(self, ga):
"""This example currently uses a 'with replacement' approach (chromosomes are placed back into the pool after participating)"""
tournament_size = int(len(ga.population.get_all_chromosomes())/10) #currently hard-coded for purposes of the example.
#selection_probability is the likelihood that a chromosome will be selected.
#best chromosome in a tournament is given a selection probablity of selection_probability
#2nd best is given probability of selection_probability*(1-selection_probability)
selection_probability = 0.95
total_selected = 0 #Total Chromosomes selected
while (total_selected <= ga.population_size*2):
#create & gather tournament group
tournament_group = []
for i in range(tournament_size):
tournament_group.append(random.choice(ga.population.get_all_chromosomes()))
#Sort the tournament contenders based on their fitness
#currently hard-coded to only consider higher fitness = better; can be changed once this impl is agreed on
#also currently uses bubble sort because its easy
tournament_group_temp = tournament_group
not_sorted_check = 0
while (not_sorted_check != len(tournament_group_temp)):
not_sorted_check = 0
for i in range(len(tournament_group_temp)):
if ((i + 1 < len(tournament_group_temp)) and (tournament_group_temp[i + 1].fitness > tournament_group_temp[i].fitness)):
temp = tournament_group[i]
tournament_group_temp[i] = tournament_group[i + 1]
tournament_group_temp[i + 1] = temp
else:
not_sorted_check += 1
tournament_group = tournament_group_temp
#After sorting by fitness, randomly select a chromosome based on selection_probability
for i in range(tournament_size):
random_num = random.uniform(0,1)
#ugly implementation but its functional
if i == 0:
if random_num <= selection_probability:
tournament_group[i].selected = True
total_selected += 1
break
else:
if random_num <= selection_probability*((1-selection_probability)**(i-1)):
tournament_group[i].selected = True
total_selected += 1
break
new_population = ga.crossover_impl(ga)
#If the crossover doesn't create enough chromosomes (ugly right now pls no judgerino, can be changed)
#Just does single-point crossover at random indices
while len(new_population.chromosomes) < ga.population_size:
crossover_pool = []
for i in range(ga.population_size):
if ga.population.get_all_chromosomes()[i].selected:
crossover_pool.append(ga.population.get_all_chromosomes()[i])
split_point = random.randint(0,ga.chromosome_length)
chromosome_list = []
for i in range(len(crossover_pool)):
if i + 1 < len(crossover_pool):
new_gene_set = []
parent_one = crossover_pool[i].get_genes()
parent_two = crossover_pool[i+1].get_genes()
new_gene_set.extend(parent_one[0:split_point])
new_gene_set.extend(parent_two[split_point:])
new_chromosome = Chromosome(new_gene_set)
chromosome_list.append(new_chromosome)
for i in range(len(chromosome_list)):
new_population.add_chromosome(chromosome_list[i])
if len(new_population.chromosomes) >= ga.population_size:
break
new_chromosome_set = ga.mutation_impl(ga, new_population.get_all_chromosomes())
new_population.set_all_chromosomes(new_chromosome_set)
return new_population
def roulette_selection(self, ga):
"""Roulette selection works based off of how strong the fitness is of the
chromosomes in the population. The stronger the fitness the higher the probability
that it will be selected. Using the example of a casino roulette wheel.
Where the chromosomes are the numbers to be selected and the board size for
those numbers are directly proportional to the chromosome's current fitness. Where
the ball falls is a randomly generated number between 0 and 1"""
pass

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@ -0,0 +1,2 @@
# FROM (. means local) file_name IMPORT class name
from .termination_types import Termination_Types

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@ -0,0 +1,16 @@
class Termination_Types:
"""Example functions that can be used to terminate the the algorithms loop"""
def fitness_based(self, ga):
"""Fitness based approach to terminate when the goal fitness has been reached"""
continue_status = True
if(ga.current_fitness > ga.fitness_goal):
continue_status = False
return continue_status
def generation_based(self, ga):
"""Generation based approach to terminate when the goal generation has been reached"""
continue_status = True
if(ga.current_generation > ga.generation_goal-1):
continue_status = False
return continue_status