def METHOD_NAME(n):
    global Ez, i, j
    t = T0 + n*dt
    if n == 0:
        return Ez, t
    else:
        Bx1[:, 1:-1] = c1 * Bx0[:, 1:-1] - c2 * (Ez[:, 1:] - Ez[:, 0:-1])
        By1[1:-1, :] = c3 * By0[1:-1, :] + c4 * (Ez[1:, :] - Ez[0:-1, :])
        Hx[:, 1:-1] += c5 * Bx1[:, 1:-1] - c6 * Bx0[:, 1:-1]
        Hy[1:-1, :] += c7 * By1[1:-1, :] - c8 * By0[1:-1, :]
        Dz1 = c9 * Dz0 + c10 * (Hy[1:, :] - Hy[0:-1, :] - Hx[:, 1:] + Hx[:, 0:-1])
        Ez *= c11
        Ez += c12 * (Dz1 - Dz0)
        Ez[i, j] = np.sin(2 * np.pi * n * (R / ND))
        Bx0[:] = Bx1
        By0[:] = By1
        Dz0[:] = Dz1
        return Ez, t