[SciPy-dev] is PySparse required for scipy.maxentropy

[Nathan Bell]

On Fri, Jan 23, 2009 at 1:50 PM,  <josef.pktd at gmail.com> wrote:
> historic artifact or not?
>
> I saw a reference to PySparse in scipy.maxentropy.maxentutils.sparsefeatures.
> Is this still required or covered by scipy.sparse?
>
> def sparsefeatures(f, x, format='csc_matrix'):
>    """ Returns an Mx1 sparse matrix of non-zero evaluations of the
>    scalar functions f_1,...,f_m in the list f at the point x.
>
>    If format='ll_mat', the PySparse module (or a symlink to it) must be
>    available in the Python site-packages/ directory.  A trimmed-down
>    version, patched for NumPy compatibility, is available in the SciPy
>    sandbox/pysparse directory.
>    """
>    m = len(f)
>    if format == 'll_mat':
>        import spmatrix
>        sparsef = spmatrix.ll_mat(m, 1)

scipy.sparse should have an equivalent format for everything PySparse
provided.  The ll_mat would correspond to sparse.lil_matrix.

Ideally, the 'format' parameter usage should be made to agree with
what we do in scipy.sparse.  For instance:
http://projects.scipy.org/scipy/scipy/browser/trunk/scipy/sparse/construct.py#L57

-- 
Nathan Bell wnbell at gmail.com
http://graphics.cs.uiuc.edu/~wnbell/