time_idx = np.where(time[:] == '1948-01-01')[0][0] IndexError: index 0 is out of bounds for axis 0 with size 0是什么问题
时间: 2024-05-28 11:14:14 浏览: 126
这个错误通常是由于数组或列表中没有找到所需的元素而引起的。
在这个例子中,看起来是 `time` 数组中没有包含字符串 `'1948-01-01'`,因此 `np.where(time[:] == '1948-01-01')[0]` 返回一个空数组,导致尝试访问其第一个元素时出现 IndexError。
你可以通过打印 `time` 数组来确认它是否包含该字符串。如果没有,你需要检查代码中的错误,并确保在 `time` 数组中包含所需的日期字符串。
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time_idx = np.where(time[:] == '1948-01-01T00:00:00Z')[0][0] IndexError: index 0 is out of bounds for axis 0 with size 0是什么问题
这个错误通常发生在使用`np.where`函数时,返回的索引数组为空时。在这种情况下,访问数组的第一个元素会导致`IndexError`。
具体来说,这个错误是说在`time`数组中找不到值为`'1948-01-01T00:00:00Z'`的元素,即返回的索引数组为空。因此,当你尝试访问空数组的第一个元素时,就会出现`IndexError: index 0 is out of bounds for axis 0 with size 0`的错误。
你需要检查一下数据中是否存在`'1948-01-01T00:00:00Z'`这个时间戳,或者检查一下代码中用于生成`time`数组的逻辑是否正确。
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[:])
```
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