sim.py 文件源码

def __init__(self, x, y):
        x = np.asarray(x, dtype=float)
        y = np.asarray(y, dtype=float)

        n = x.shape[0]
        dx = np.diff(x)
        dy = np.diff(y, axis=0)
        dxr = dx.reshape([dx.shape[0]] + [1] * (y.ndim - 1))

        c = np.empty((3, n - 1) + y.shape[1:])
        if n > 2:
            A = np.ones((2, n))
            b = np.empty((n,) + y.shape[1:])
            b[0] = 0
            b[1:] = 2 * dy / dxr
            s = solve_banded((1, 0), A, b, overwrite_ab=True, overwrite_b=True,
                             check_finite=False)
            c[0] = np.diff(s, axis=0) / (2 * dxr)
            c[1] = s[:-1]
            c[2] = y[:-1]
        else:
            c[0] = 0
            c[1] = dy / dxr
            c[2] = y[:-1]

        super(_QuadraticSpline, self).__init__(c, x)