util.py 文件源码

def coherence_of_columns(A):
    """Mutual coherence of columns of A.

    Parameters
    ----------
    A : array_like
        Input matrix.
    p : int, optional
        p-th norm.

    Returns
    -------
    array_like
        Mutual coherence of columns of A.
    """
    A = np.asmatrix(A)
    _, N = A.shape
    A = A * np.asmatrix(np.diag(1/norm_of_columns(A)))
    Gram_A = A.H*A
    for j in range(N):
        Gram_A[j, j] = 0
    return np.max(np.abs(Gram_A))