def __calc_A(self, h):
    '\n        calc matrix A for spline coefficient c\n        '
    A = np.zeros((self.nx, self.nx))
    A[(0, 0)] = 1.0
    for i in range((self.nx - 1)):
        if (i != (self.nx - 2)):
            A[((i + 1), (i + 1))] = (2.0 * (h[i] + h[(i + 1)]))
        A[((i + 1), i)] = h[i]
        A[(i, (i + 1))] = h[i]
    A[(0, 1)] = 0.0
    A[((self.nx - 1), (self.nx - 2))] = 0.0
    A[((self.nx - 1), (self.nx - 1))] = 1.0
    return A
calc matrix A for spline coefficient c
def __calc_A(self, h):
    '\n        \n        '
    A = np.zeros((self.nx, self.nx))
    A[(0, 0)] = 1.0
    for i in range((self.nx - 1)):
        if (i != (self.nx - 2)):
            A[((i + 1), (i + 1))] = (2.0 * (h[i] + h[(i + 1)]))
        A[((i + 1), i)] = h[i]
        A[(i, (i + 1))] = h[i]
    A[(0, 1)] = 0.0
    A[((self.nx - 1), (self.nx - 2))] = 0.0
    A[((self.nx - 1), (self.nx - 1))] = 1.0
    return A