autocorr.py 文件源码

def plot_correlate():
    """Plots the autocorrelation function computed by numpy.
    """
    wave = thinkdsp.read_wave('28042__bcjordan__voicedownbew.wav')
    wave.normalize()
    segment = wave.segment(start=0.2, duration=0.01)

    lags, corrs = autocorr(segment)

    corrs2 = numpy.correlate(segment.ys, segment.ys, mode='same')
    thinkplot.plot(corrs2)
    thinkplot.config(xlabel='lag', 
                     ylabel='correlation', 
                     xlim=[0, len(corrs2)])
    thinkplot.save(root='autocorr9')

    N = len(corrs2)
    half = corrs2[N//2:]

    lengths = range(N, N//2, -1)
    half /= lengths
    half /= half[0]