scipy로 필터링

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import scipy as sp
import numpy as np
import matplotlib.pyplot as plt
from scipy import signal

if __name__ == '__main__':
    #64タップで通過域が0〜0.25, 阻止域が0.3〜0.5なフィルタ
    taps = 64;
    edge = [ 0,  0.25 , 0.3, 0.5 ]
    gain = [ 1.0,  0.000 ]
    weight = [ 0.2, 1.0 ]

    remez_impres = sp.signal.remez( taps,  edge, gain )
    remez_freq, remez_fresponse = sp.signal.freqz( remez_impres )
    remez_amp = np.abs( remez_fresponse )

    wf_impres = sp.signal.firwin( taps, 2.0 * edge[1] );
    wf_freq, wf_fresponse = sp.signal.freqz( wf_impres )
    wf_amp = np.abs( wf_fresponse )

    plt.subplot(221)
    plt.semilogy( remez_freq / ( 2 * np.pi ),  remez_amp, 'b-' )
    plt.title( 'Frequency Response( Remez )' )

    plt.subplot(222)
    plt.plot( remez_impres, 'b-' )
    plt.title( 'Impres Response( Remez )' )

    plt.subplot(223)
    plt.semilogy( wf_freq / ( 2 * np.pi ),  wf_amp, 'b-' )
    plt.title( 'Frequency Response( Window )' )

    plt.subplot(224)
    plt.plot( wf_impres, 'b-' )
    plt.title( 'Impres Response( Window )' )
    plt.show()