si23traktor/agent/methods/genetic_algorithm.py

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2023-06-18 23:37:30 +02:00
import numpy as np
import random
import math
def create_initial_population(num_cities, population_size, list):
population = []
for _ in range(population_size):
chromosome = list.copy()
chromosome.remove((1, 1)) # Usuń punkt (1, 1) z listy
random.shuffle(chromosome)
chromosome.insert(0, (1, 1)) # Dodaj punkt (1, 1) na początku trasy
population.append(chromosome)
return population
def calculate_distance(city1, city2):
x1, y1 = city1
x2, y2 = city2
distance = math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2)
return distance
def calculate_fitness(individual):
total_distance = 0
num_cities = len(individual)
for i in range(num_cities - 1):
city1 = individual[i]
city2 = individual[i + 1]
distance = calculate_distance(city1, city2)
total_distance += distance
fitness = 1 / total_distance
return fitness
def crossover(parent1, parent2):
child = [(1, 1)] + [None] * (len(parent1) - 1) # Inicjalizacja dziecka z punktem (1, 1) na początku
start_index = random.randint(1, len(parent1) - 1)
end_index = random.randint(start_index + 1, len(parent1))
# Skopiuj fragment miast od parent1 do dziecka
child[start_index:end_index] = parent1[start_index:end_index]
# Uzupełnij brakujące miasta z parent2
remaining_cities = [city for city in parent2 if city not in child]
child[1:start_index] = remaining_cities[:start_index - 1]
child[end_index:] = remaining_cities[start_index - 1:]
return child
def mutate(individual, mutation_rate):
for i in range(1, len(individual)): # Rozpoczynamy od indeksu 1, aby pominąć punkt (1, 1)
if random.random() < mutation_rate:
j = random.randint(1, len(individual) - 1) # Wybieramy indeks od 1 do ostatniego indeksu
individual[i], individual[j] = individual[j], individual[i]
return individual
def genetic_algorithm(list):
chromosome_length = 21
max_generations = 200
population_size = 200
crossover_rate = 0.25
mutation_rate = 0.1
num_cities = chromosome_length
population = create_initial_population(num_cities, population_size, list)
best_individual = None
best_fitness = float('-inf')
for generation in range(max_generations):
# # Oblicz wartości fitness dla każdego osobnika w populacji
# fitness_values = [calculate_fitness(individual) for individual in population]
# population = [x for _, x in sorted(zip(fitness_values, population), reverse=True)]
# fitness_values.sort(reverse=True)
# max_fitness_index = np.argmax(fitness_values)
# # Wybierz najlepszego osobnika z ostatniej populacji
# if fitness_values[max_fitness_index] > best_fitness:
# best_fitness = fitness_values[max_fitness_index]
# best_individual = population[max_fitness_index]
# # Twórz nową populację z krzyżówek
# new_population = []
# for _ in range(int(population_size / 2)):
# parent1, parent2 = random.choices(population[:population_size // 2], k=2)
# child1 = crossover(parent1, parent2)
# child2 = crossover(parent2, parent1)
# new_population.extend([child1, child2])
# # Dokonaj mutacji na nowej populacji
# new_population = [mutate(individual, mutation_rate) for individual in new_population]
# population = new_population
# Oblicz wartości fitness dla każdego osobnika w populacji
fitness_values = [calculate_fitness(individual) for individual in population]
population = [x for _, x in sorted(zip(fitness_values, population), reverse=True)]
fitness_values.sort(reverse=True)
best_individuals = population[:10] # Wybierz k najlepszych osobników
new_population = best_individuals.copy()
# Twórz nową populację z krzyżówek i mutacji
while len(new_population) < population_size:
parent1, parent2 = random.choices(best_individuals, k=2) # Wybierz rodziców spośród najlepszych osobników
child = crossover(parent1, parent2) # Krzyżowanie
child = mutate(child, mutation_rate) # Mutacja
new_population.append(child)
for individual in best_individuals:
fitness = calculate_fitness(individual)
if fitness > best_fitness:
best_fitness = fitness
best_individual = individual
population = new_population[:population_size]
print("Best path:", best_individual)
return best_individual