signal_data_features.py 文件源码

def get_dct(x, n_dct):
    """
    Renvoie les n_dct plus grands coefficients de la transformée en 
    cosinus discrète 
    """
    # Compute FFT coefficients (complex)
    coeffs = dct(x.transpose())
    # Sort according to absolute value
    coeffs_sorted = coeffs.ravel()[np.argsort(-np.abs(coeffs)).ravel()] \
    .reshape(coeffs.shape)
    # n_fft largest coefficients
    n_coeffs = coeffs_sorted[:,:n_dct]
    # Return the coefficients
    return n_coeffs