用python写一个基于遗传算法的船舶调度问题代码考虑船舶长度、吃水深度、到达时间、停留时间泊位长度、泊位深度、泊位潮汐变化泊位潮汐变化遵循正弦函数。泊位有多个总时长T=1440泊位潮汐变化为2sin2nppixT - draft当时刻为x该泊位初始深度为draft时
由于题目比较复杂,以下是一个基本的遗传算法框架,需要根据具体情况进行修改和完善。
import random
import numpy as np
# 定义船舶类
class Ship:
def __init__(self, length, draft, arrive_time, stay_time):
self.length = length
self.draft = draft
self.arrive_time = arrive_time
self.stay_time = stay_time
# 定义泊位类
class Berth:
def __init__(self, length, draft, tidal_range):
self.length = length
self.draft = draft
self.tidal_range = tidal_range
# 生成初始种群
def generate_population(ship_list, berth_list, population_size):
population = []
for i in range(population_size):
schedule = []
for ship in ship_list:
berth = random.choice(berth_list)
schedule.append((ship, berth))
population.append(schedule)
return population
# 评估适应度
def evaluate_fitness(schedule, T):
fitness = 0
for i in range(len(schedule)):
ship, berth = schedule[i]
start_time = max(ship.arrive_time, berth.tidal_range[0]) # 船只开始停靠时间
end_time = start_time + ship.stay_time # 船只结束停靠时间
if end_time > T: # 船只停靠时间超出总时长
fitness -= 100 # 惩罚
else:
# 判断泊位是否可用
flag = True
for j in range(i):
if schedule[j][1] == berth:
other_ship, _ = schedule[j]
other_start_time = max(other_ship.arrive_time, berth.tidal_range[0])
other_end_time = other_start_time + other_ship.stay_time
if (start_time < other_end_time) and (end_time > other_start_time):
flag = False # 泊位被占用
break
if flag:
fitness += 1 # 可用泊位加分
return fitness
# 选择
def selection(population, fitness):
selected_population = []
total_fitness = sum(fitness)
probabilities = [f / total_fitness for f in fitness] # 计算每个个体被选中的概率
for i in range(len(population)):
selected_population.append(random.choices(population, probabilities)[0])
return selected_population
# 交叉
def crossover(parent1, parent2):
point = random.randint(1, len(parent1) - 1)
child1 = parent1[:point] + parent2[point:]
child2 = parent2[:point] + parent1[point:]
return child1, child2
# 变异
def mutation(schedule, ship_list, berth_list):
for i in range(len(schedule)):
if random.random() < mutation_rate:
ship, _ = schedule[i]
new_berth = random.choice(berth_list)
schedule[i] = (ship, new_berth)
return schedule
# 遗传算法
def genetic_algorithm(ship_list, berth_list, T, population_size, num_generations, mutation_rate):
# 生成初始种群
population = generate_population(ship_list, berth_list, population_size)
for generation in range(num_generations):
# 评估适应度
fitness = [evaluate_fitness(schedule, T) for schedule in population]
# 选择
selected_population = selection(population, fitness)
# 交叉
next_population = []
for i in range(0, len(selected_population), 2):
parent1 = selected_population[i]
parent2 = selected_population[i+1]
child1, child2 = crossover(parent1, parent2)
next_population.append(child1)
next_population.append(child2)
# 变异
next_population = [mutation(schedule, ship_list, berth_list) for schedule in next_population]
# 更新种群
population = next_population
# 评估适应度并返回最优解
fitness = [evaluate_fitness(schedule, T) for schedule in population]
best_schedule = population[np.argmax(fitness)]
return best_schedule
需要注意的是,以上代码中的泊位潮汐变化函数只考虑了周期为一天的情况,如果周期不同需要进行相应的修改。同时,评估适应度的函数也需要根据具体情况进行修改,例如加入考虑船只长度、吃水深度等因素的计算
原文地址: http://www.cveoy.top/t/topic/hlMb 著作权归作者所有。请勿转载和采集!