SoundUtils.py 文件源码

def Heterodyn(x, f, sr=1, nwind=1024, nhop=512,
              windfunc=np.blackman):
    '''
    Calculates the amplitude near frequency f in x

    nwind should be at least 3 periods if the signal is periodic.
    '''
    sinsig = np.exp(2j*np.pi*np.arange(len(x))*f/float(sr))
    hamp, t = FuncWind(np.sum, x*sinsig, power=1, sr=sr,
                       nwind=nwind, nhop=nhop,
                       windfunc=windfunc)
    return np.array(hamp)*2, np.array(t)