def lanczos_eigs(A: LinearOperator, start_vector: Array = None, max_iters: int = 100, tol: float = 1e-7,
                 pbar: bool = False, key=None):
    """
    Computes the eigenvalues and eigenvectors using Lanczos.

    Args:
        A (LinearOperator): A symmetric linear operator of size (n, n).
        start_vector (Array, optional): An initial vector to start Lanczos of size (n, ).
         Defaults to a random probe.
        max_iters (int): The maximum number of iterations to run.
        tol (float, optional): Stopping criteria.
        pbar (bool, optional): Show a progress bar.
        key (PNRGKey, optional): PRNGKey for random number generation.

    Returns:
        tuple:
            - eigvals (Array): eigenvalues of shape (max_iters,).
            - eigvectors (LinearOperator): eigenvectors of shape (n, max_iters).
            - info (dict): General information about the iterative procedure.

    """
    xnp = A.xnp
    Q, T, info = lanczos(A=A, start_vector=start_vector, max_iters=max_iters, tol=tol, pbar=pbar, key=key)
    eigvals, eigvectors = xnp.eigh(T.to_dense())
    idx = xnp.argsort(eigvals, axis=-1)
    V = Q @ lazify(eigvectors[:, idx])
    eigvals = eigvals[..., idx]
    return eigvals, V, info

    Computes the eigenvalues and eigenvectors using Lanczos.

    Args:
        A (LinearOperator): A symmetric linear operator of size (n, n).
        start_vector (Array, optional): An initial vector to start Lanczos of size (n, ).
         Defaults to a random probe.
        max_iters (int): The maximum number of iterations to run.
        tol (float, optional): Stopping criteria.
        pbar (bool, optional): Show a progress bar.
        key (PNRGKey, optional): PRNGKey for random number generation.

    Returns:
        tuple:
            - eigvals (Array): eigenvalues of shape (max_iters,).
            - eigvectors (LinearOperator): eigenvectors of shape (n, max_iters).
            - info (dict): General information about the iterative procedure.

    
cola/linalg/decompositions/lanczos.py