为什么元素计算不正确？

Question

在我调用函数后，有人能解释为什么y的所有元素都等于零吗？

import matplotlib.pyplot as plt
import numpy as np
def hilbertImpulseResponse(k):
if k == 0: 
return 0
else: 
return ((2/(np.pi*k)) * (np.sin((np.pi*k)/2)) * (np.sin((np.pi*k)/2)))
size = 5
n = np.arange(-size, size + 1)
y = np.arange(-size, size + 1)
for i in np.arange(-size, size + 1):
y[i] = hilbertImpulseResponse(i)
print(y)

提前感谢

Answer 1

np.arange正在将dtype推断为np.int64。所以所有的价值观都被打破了！

尝试指定dtype:

import matplotlib.pyplot as plt
import numpy as np
def hilbertImpulseResponse(k):
if k == 0: 
return 0
else: 
return ((2/(np.pi*k)) * (np.sin((np.pi*k)/2)) * (np.sin((np.pi*k)/2)))
size = 5
n = np.arange(-size, size + 1, dtype=np.float64)
y = np.arange(-size, size + 1, dtype=np.float64)
for i in np.arange(-size, size + 1):
y[i] = hilbertImpulseResponse(i)
print(y)

Answer 2

您希望如何在剩下的过程中使用y？最好将这些值存储在标准Pythondict:中

import matplotlib.pyplot as plt
import numpy as np
def hilbertImpulseResponse(k):
if k == 0: 
return 0
else: 
return ((2/(np.pi*k)) * (np.sin((np.pi*k)/2)) * (np.sin((np.pi*k)/2)))
size = 5
y = {i:hilbertImpulseResponse(i) for i in range(-size, size + 1)}
print(y)

或者可能是双重的：

y = [(i,hilbertImpulseResponse(i)) for i in range(-size, size + 1)]

或者甚至在需要时仅生成CCD_ 7值。