analog.py 文件源码

def _passthrough_delay(m, c):
    """Analytically derived state-space when p = q = m.

    We use this because it is numerically stable for high m.
    """
    j = np.arange(1, m+1, dtype=np.float64)
    u = (m + j) * (m - j + 1) / (c * j)

    A = np.zeros((m, m))
    B = np.zeros((m, 1))
    C = np.zeros((1, m))
    D = np.zeros((1,))

    A[0, :] = B[0, 0] = -u[0]
    A[1:, :-1][np.diag_indices(m-1)] = u[1:]
    D[0] = (-1)**m
    C[0, np.arange(m) % 2 == 0] = 2*D[0]
    return LinearSystem((A, B, C, D), analog=True)