(A)
return csr_matrix((np.asarray(A), np.arange(len(A)),
                       np.arange(len(A)+1)), (len(A), len(A)))
Return a diagonal.

    If A is a sparse matrix (e.g. csr_matrix or csc_matrix)
       - return the diagonal of A as an array

    Otherwise
       - return a csr_matrix with A on the diagonal

    Parameters
    ----------
    A : sparse matrix or 1d array
        General sparse matrix or array of diagonal entries

    Returns
    -------
    B : array or sparse matrix
        Diagonal sparse is returned as csr if A is dense otherwise return an
        array of the diagonal

    Examples
    --------
    >>> import numpy as np
    >>> from pyamg.util.utils import diag_sparse
    >>> d = 2.0*np.ones((3,)).ravel()
    >>> print(diag_sparse(d).toarray())
    [[2. 0. 0.]
     [0. 2. 0.]
     [0. 0. 2.]]
Return a diagonal.
Return a diagonal .
def diag_sparse(A):
    """Return a diagonal.

    If A is a sparse matrix (e.g. csr_matrix or csc_matrix)
       - return the diagonal of A as an array

    Otherwise
       - return a csr_matrix with A on the diagonal

    Parameters
    ----------
    A : sparse matrix or 1d array
        General sparse matrix or array of diagonal entries

    Returns
    -------
    B : array or sparse matrix
        Diagonal sparse is returned as csr if A is dense otherwise return an
        array of the diagonal

    Examples
    --------
    >>> import numpy as np
    >>> from pyamg.util.utils import diag_sparse
    >>> d = 2.0*np.ones((3,)).ravel()
    >>> print(diag_sparse(d).toarray())
    [[2. 0. 0.]
     [0. 2. 0.]
     [0. 0. 2.]]

    """
    if isspmatrix(A):
        return A.diagonal()

    if np.ndim(A) != 1:
        raise ValueError('input diagonal array expected to be 1d')

    return csr_matrix((np.asarray(A), np.arange(len(A)),
                       np.arange(len(A)+1)), (len(A), len(A)))
def diag_sparse ( A ) : if isspmatrix ( A ) : return A . diagonal ( ) if np . ndim ( A ) != 1 : raise ValueError ( 'input diagonal array expected to be 1d' ) return csr_matrix ( ( np . asarray ( A ) , np . arange ( len ( A ) ) , np . arange ( len ( A ) + 1 ) ) , ( len ( A ) , len ( A ) ) )