#
# Imports
#
from scipy import signal
from matplotlib import pyplot as plt
from matplotlib import style
from scipy.fftpack import fft, fftshift
import numpy as np


#
# Global variables
#


#
# Private functions
#



#
# main
#
if __name__ == "__main__":
    window = signal.parzen(51)
    plt.plot(window)
    plt.title("Parzen Window")
    plt.ylabel("Amplitude")
    plt.xlabel("Sample")

    plt.figure()

    A = fft(window,2048)/(len(window)/2.0)
    freq = np.linspace(-0.5,0.5,len(A))
    response = 20*np.log10(np.abs(fftshift(A/abs(A).max())))
    plt.plot(freq,response)
    plt.axis([-0.5,0.5,-120,0])
    plt.title("Frequency response of the Parzen Window")
    plt.ylabel("Normalized magnitude(dB)")
    plt.xlabel("Normalized frequency in (cycles/sample)")

    plt.show()
