Traceback (most recent call last): File "D:/pycharm/pythonProject1/moni 1.py", line 18, in <module> start_time = time.time() NameError: name 'time' is not defined

这个错误是因为代码中使用了`time`模块，但是没有导入该模块。为了解决这个问题，需要在代码的开头添加以下语句来导入`time`模块：

import time

完整的代码如下：

import numpy as np
import sys
import time

# 定义多项式计算函数
def poly_eval(x, coef):
    n = len(coef)
    res = coef[0]
    for i in range(1, n):
        res = res * x + coef[i]
    return res

# 生成500个节点的多项式系数
poly_coef = np.random.randn(501)

# 测试多项式计算时间和内存使用
x = np.random.rand()
print("Testing polynomial evaluation with 500 nodes...")
start_time = time.time()
result = poly_eval(x, poly_coef)
end_time = time.time()
elapsed_time = end_time - start_time
memory_usage = sys.getsizeof(poly_coef) / 1024 / 1024
print("Result:", result)
print("Elapsed time:", elapsed_time, "seconds")
print("Memory usage:", memory_usage, "MB")

# 将500个节点分为10个区域
n_regions = 10
region_size = 50
region_starts = np.arange(n_regions) * region_size
region_ends = region_starts + region_size

# 分区多项式计算函数
def region_poly_eval(x, region_coefs, region_starts):
    res = 0
    for i in range(len(region_coefs)):
        coef = region_coefs[i]
        start = region_starts[i]
        res += poly_eval(x**(start+1), coef)
    return res

# 计算每个区域的多项式系数
region_coefs = []
for i in range(n_regions):
    region_coef = poly_coef[region_starts[i]:region_ends[i]+1]
    region_coefs.append(region_coef)

# 测试分区多项式计算时间和内存使用
x = np.random.rand()
print("Testing polynomial evaluation with 10 regions...")
start_time = time.time()
result = region_poly_eval(x, region_coefs, region_starts)
end_time = time.time()
elapsed_time = end_time - start_time
memory_usage = sum([sys.getsizeof(coef) for coef in region_coefs]) / 1024 / 1024
print("Result:", result)
print("Elapsed time:", elapsed_time, "seconds")
print("Memory usage:", memory_usage, "MB")

现在你可以运行这个代码了，它将计算多项式的值和运行时间，并比较将500个节点分区后的结果。