def spdar1(ar, w):
    if np.ndim(ar) == 0:
        rho = ar
    else:
        rho = -ar[1]
    return 0.5 / np.pi /(1 + rho*rho - 2 * rho * np.cos(w))
dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/sandbox/tsa/fftarma.py/spdar1/original