python 傅裡葉曲線拟合

本文在python 傅裡葉曲線拟合的基礎上對拟合函數做了修正

def fourier(x, *args):
    t = np.arange(0, np.pi, np.pi/len(args)*2)
    w = 2 * np.pi / 200
    m = int(len(args) / 2)
    arr = np.zeros((m, 2))
    arr[:, 0] = np.array(args[:m:1])
    arr[:, 1] = np.array(args[-1:-m-1:-1])
    ret = np.sum(np.cos(t.reshape(-1, 1) * w * x).T * arr[:, 0].reshape(1, -1)
                 + np.sin(t.reshape(-1, 1) * w * x).T * arr[:, 1].reshape(1, -1),
                 axis=1)
    # ret = 0
    # for deg in range(0, int(len(args) / 2) + 1):
    #     ret += args[deg] * np.cos(deg * w * x) + args[len(args) - deg - 1] * np.sin(deg * w * x)

    return ret
           

将for循環的形式修改為矩陣計算,性能有較大提升.