Numpy | Python 中的汉宁
汉宁窗是使用加权余弦形成的锥度。
Syntax: numpy.hamming(M)
Parameters:
M : Number of points in the output window.
Returns: AN array
窗口，最大值归一化为 1(值 1 仅在 M 为奇数时出现)。
代码#1:
import numpy as np
print(np.hanning(12))
输出:
[ 0\. 0.07937323 0.29229249 0.57115742 0.82743037 0.97974649
0.97974649 0.82743037 0.57115742 0.29229249 0.07937323 0\. ]
代码#2: 绘制窗口及其频率响应(需要 SciPy 和 matplotlib)。
import numpy as np
import matplotlib.pyplot as plt
from numpy.fft import fft, fftshift
window = np.hanning(51)
plt.plot(window)
plt.title("Hann window")
plt.ylabel("Amplitude"")
plt.xlabel("Sample")
plt.show()
输出:
频率:
import numpy as np
import matplotlib.pyplot as plt
from numpy.fft import fft, fftshift
window = np.hanning(51)
plt.figure()
A = fft(window, 2048) / 25.5
mag = np.abs(fftshift(A))
freq = np.linspace(-0.5, 0.5, len(A))
response = 20 * np.log10(mag)
response = np.clip(response, -100, 100)
plt.plot(freq, response)
plt.title("Frequency response of Hanning window")
plt.ylabel("Magnitude [dB]")
plt.xlabel("Normalized frequency [cycles per sample]")
plt.axis("tight")
plt.show()
输出:
