Hanning at Numpy | python



Hanning Window — it is a weighted cosine cone.

  Syntax:  numpy.hamming (M)  Parameters:   M:  Number of points in the output window.  Returns:  AN array 

Window with maximum value normalized to one (value one appears only if M is odd).

Code # 1 :

import numpy as np

 

 

print (np.hanning ( 12 ))

Exit:

 [0. 0.07937323 0.29229249 0.57115742 0.82743037 0.97974649 0.97974649 0.82743037 0.57115742 0.29229249 0.07937323 0.] 

Code # 2: Plotting a window plot and its frequency response (requires SciPy and matplot

p>

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 & amp; quot " )

plt.xlabel ( "Sample" )

 
plt.show ()

Output:

For frequency:

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 ()

Output: