def __calc_B(self, h):
    '\n        calc matrix B for spline coefficient c\n        '
    B = np.zeros(self.nx)
    for i in range((self.nx - 2)):
        B[(i + 1)] = (((3.0 * (self.a[(i + 2)] - self.a[(i + 1)])) / h[(i + 1)]) - ((3.0 * (self.a[(i + 1)] - self.a[i])) / h[i]))
    return B
calc matrix B for spline coefficient c
def __calc_B(self, h):
    '\n        \n        '
    B = np.zeros(self.nx)
    for i in range((self.nx - 2)):
        B[(i + 1)] = (((3.0 * (self.a[(i + 2)] - self.a[(i + 1)])) / h[(i + 1)]) - ((3.0 * (self.a[(i + 1)] - self.a[i])) / h[i]))
    return B