class Generations(): def __init__(self): self.generations = [] def first_generation(self): out = [] for i in range(population): nn = NeuroNetwork() nn.init_neuro_network(network[0], network[1], network[2]) out.append(nn.get_weights()) self.generations.append(Generation()) return out def next_generation(self): if len(self.generations) == 0: return False gen = self.generations[-1].generate_next_generation() self.generations.append(Generation()) return gen def add_genome(self, genome): if len(self.generations) == 0: return False return self.generations[-1].add_genome(genome)
时间: 2024-02-10 08:18:01 浏览: 28
这段代码是一个遗传算法的实现,用于生成和演化神经网络的权重,以优化神经网络的性能。
具体来说,这个遗传算法包含了一个 Generation 类和一个 Generations 类。Generation 类表示一个代,包含了多个 Genome(基因组),每个 Genome 表示一个神经网络的权重。Generations 类则表示多个代,通过不断演化神经网络的权重,逐步提高神经网络的性能。
在 first_generation 方法中,通过随机初始化多个神经网络的权重,生成第一代的多个 Genome,返回这些 Genome 的权重作为第一代的神经网络。
在 next_generation 方法中,通过上一代的 Genome,使用遗传算法生成新的 Genome,作为下一代的神经网络权重。
在 add_genome 方法中,将新的 Genome 添加到当前代的 Generation 中。
通过不断迭代和演化,神经网络的性能逐渐提高,以适应特定的任务。
相关问题
import numpy as np from platypus import NSGAII, Problem, Real, Integer # 定义问题 class JobShopProblem(Problem): def __init__(self, jobs, machines, processing_times): num_jobs = len(jobs) num_machines = len(machines[0]) super().__init__(num_jobs, 1, 1) self.jobs = jobs self.machines = machines self.processing_times = processing_times self.types[:] = Integer(0, num_jobs - 1) self.constraints[:] = [lambda x: x[0] == 1] def evaluate(self, solution): job_order = np.argsort(np.array(solution.variables[:], dtype=int)) machine_available_time = np.zeros(len(self.machines)) job_completion_time = np.zeros(len(self.jobs)) for job_idx in job_order: job = self.jobs[job_idx] for machine_idx, processing_time in zip(job, self.processing_times[job_idx]): machine_available_time[machine_idx] = max(machine_available_time[machine_idx], job_completion_time[job_idx]) job_completion_time[job_idx] = machine_available_time[machine_idx] + processing_time solution.objectives[:] = [np.max(job_completion_time)] # 定义问题参数 jobs = [[0, 1], [2, 0], [1, 2]] machines = [[0, 1, 2], [1, 2, 0], [2, 0, 1]] processing_times = [[5, 4], [3, 5], [1, 3]] # 创建算法实例 problem = JobShopProblem(jobs, machines, processing_times) algorithm = NSGAII(problem) algorithm.population_size = 100 # 设置优化目标 problem.directions[:] = Problem.MINIMIZE # 定义算法参数 algorithm.population_size = 100 max_generations = 100 mutation_probability = 0.1 # 设置算法参数 algorithm.max_iterations = max_generations algorithm.mutation_probability = mutation_probability # 运行算法 algorithm.run(max_generations) # 输出结果 print("最小化的最大完工时间:", algorithm.result[0].objectives[0]) print("工件加工顺序和机器安排方案:", algorithm.result[0].variables[:]) 请检查上述代码
代码的语法没有问题,但是在定义问题时,约束条件中的 lambda 函数有误。应该将 x[0] == 1 改为 x[0] == 0,因为变量的范围是 0 到 num_jobs - 1。另外,应该在 lambda 函数前加上 @staticmethod,表示这是一个静态方法。修改后的代码如下:
```
import numpy as np
from platypus import NSGAII, Problem, Real, Integer
# 定义问题
class JobShopProblem(Problem):
def __init__(self, jobs, machines, processing_times):
num_jobs = len(jobs)
num_machines = len(machines[0])
super().__init__(num_jobs, 1, 1)
self.jobs = jobs
self.machines = machines
self.processing_times = processing_times
self.types[:] = Integer(0, num_jobs - 1)
self.constraints[:] = [self.check_order]
@staticmethod
def check_order(x):
return x[0] == 0
def evaluate(self, solution):
job_order = np.argsort(np.array(solution.variables[:], dtype=int))
machine_available_time = np.zeros(len(self.machines))
job_completion_time = np.zeros(len(self.jobs))
for job_idx in job_order:
job = self.jobs[job_idx]
for machine_idx, processing_time in zip(job, self.processing_times[job_idx]):
machine_available_time[machine_idx] = max(machine_available_time[machine_idx], job_completion_time[job_idx])
job_completion_time[job_idx] = machine_available_time[machine_idx] + processing_time
solution.objectives[:] = [np.max(job_completion_time)]
# 定义问题参数
jobs = [[0, 1], [2, 0], [1, 2]]
machines = [[0, 1, 2], [1, 2, 0], [2, 0, 1]]
processing_times = [[5, 4], [3, 5], [1, 3]]
# 创建算法实例
problem = JobShopProblem(jobs, machines, processing_times)
algorithm = NSGAII(problem)
algorithm.population_size = 100
# 设置优化目标
problem.directions[:] = Problem.MINIMIZE
# 定义算法参数
algorithm.population_size = 100
max_generations = 100
mutation_probability = 0.1
# 设置算法参数
algorithm.max_iterations = max_generations
algorithm.mutation_probability = mutation_probability
# 运行算法
algorithm.run(max_generations)
# 输出结果
print("最小化的最大完工时间:", algorithm.result[0].objectives[0])
print("工件加工顺序和机器安排方案:", algorithm.result[0].variables[:])
```
翻译代码: best_net = None for gen in range(self.generations): parents = [] for i in range(self.pop_size): idx1 = np.random.choice(range(self.pop_size), size=self.pop_size // 2, replace=False) idx2 = np.random.choice(range(self.pop_size), size=self.pop_size // 2, replace=False) parent1 = self.pop[max(idx1, key=lambda i: fitness_scores[i])] parent2 = self.pop[max(idx2, key=lambda i: fitness_scores[i])] parents.append((parent1, parent2))
翻译如下:
```
best_net = None
for gen in range(self.generations):
parents = []
for i in range(self.pop_size):
idx1 = np.random.choice(range(self.pop_size), size=self.pop_size // 2, replace=False)
idx2 = np.random.choice(range(self.pop_size), size=self.pop_size // 2, replace=False)
parent1 = self.pop[max(idx1, key=lambda i: fitness_scores[i])]
parent2 = self.pop[max(idx2, key=lambda i: fitness_scores[i])]
parents.append((parent1, parent2))
```
意思是:
```
best_net = None # 初始化最好的神经网络
for gen in range(self.generations): # 进行多少代繁殖
parents = [] # 初始化父母列表
for i in range(self.pop_size): # 对于每一个个体
idx1 = np.random.choice(range(self.pop_size), size=self.pop_size // 2, replace=False) # 随机选择一组父母
idx2 = np.random.choice(range(self.pop_size), size=self.pop_size // 2, replace=False) # 随机选择另一组父母
parent1 = self.pop[max(idx1, key=lambda i: fitness_scores[i])] # 根据适应度选出第一个父母
parent2 = self.pop[max(idx2, key=lambda i: fitness_scores[i])] # 根据适应度选出第二个父母
parents.append((parent1, parent2)) # 将这两个父母加入到父母列表中
```
其中 `self.pop` 是神经网络的种群,`fitness_scores` 是每个神经网络的适应度得分。该段代码是在进行遗传算法的繁殖过程中选出父母,用于下一步的交叉和变异操作。