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Added Jared's comments to Roulette selection

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danielwilczak101
2020-10-13 00:03:00 -04:00
parent 9c6d5777b7
commit 2485af795a
1 changed files with 6 additions and 3 deletions
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9
src/parent_selection/parent_selection_methods.py
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@ -42,16 +42,20 @@ class Parent_Selection:
those numbers are directly proportional to the chromosome's current fitness. Where those numbers are directly proportional to the chromosome's current fitness. Where
the ball falls is a randomly generated number between 0 and 1""" the ball falls is a randomly generated number between 0 and 1"""
total_fitness = sum(ga.population.chromosome_list[i].get_fitness() for i in range(ga.population.size())) # The sum of all the fitnessess in a population
total_fitness = sum(ga.population.chromosome_list[i].get_fitness() for i in range(len(ga.population.chromosome_list)))
rel_fitnesses = [] rel_fitnesses = []
# A list of each chromosome's relative chance of getting chosen
for chromosome in ga.population.chromosome_list: for chromosome in ga.population.chromosome_list:
if (total_fitness != 0): if (total_fitness != 0):
rel_fitnesses.append(float(chromosome.fitness)/total_fitness) rel_fitnesses.append(float(chromosome.fitness)/total_fitness)
# A list of ranges that represent the probability of a chromosome getting chosen
probability = [sum(rel_fitnesses[:i+1]) for i in range(len(rel_fitnesses))] probability = [sum(rel_fitnesses[:i+1]) for i in range(len(rel_fitnesses))]
while (len(ga.population.mating_pool) < ga.population.size()*ga.parent_ratio): # Loops until it reaches a desired mating pool size
while (len(ga.population.mating_pool) < len(ga.population.get_all_chromosomes())*ga.parent_ratio):
rand_number = random.random() rand_number = random.random()
# Loop through the list of probabilities # Loop through the list of probabilities
@ -59,5 +63,4 @@ class Parent_Selection:
# If the probability is greater than the random_number, then select that chromosome # If the probability is greater than the random_number, then select that chromosome
if (probability[i] >= rand_number): if (probability[i] >= rand_number):
ga.population.mating_pool.append(ga.population.chromosome_list[i]) ga.population.mating_pool.append(ga.population.chromosome_list[i])
# print (f'Selected chromosome : {i}')
break break