_filtering.py 文件源码

def morlet(x, Fs, f, wavelet_width=7):
    dt = 1/Fs
    sf = f/wavelet_width
    st = 1/(2*np.pi*sf)
    N, nepoch = x.shape

    t = np.arange(-3.5*st, 3.5*st, dt)

    A = 1/(st*np.sqrt(np.pi))**(1/2)
    m = A*np.exp(-np.square(t)/(2*st**2))*np.exp(1j*2*np.pi*f*t)

    xMorlet = np.zeros((N, nepoch))
    for k in range(0, nepoch):
        y = 2*np.abs(np.convolve(x[:, k], m))/Fs
        xMorlet[:, k] = y[int(np.ceil(len(m)/2))-1:int(len(y)-np.floor(
            len(m)/2))]

    return xMorlet