[SciPy-dev] Sparse matrix design and broadcasting  Neilen Marais
nmarais at sun.ac.za Fri Jul 7 12:53:44 CDT 2006   I've been
looking at the scipy.sparse routines a little, specifically the
sparse_lil type. Currently fancy indexing seems to be handled by
a lot of special case code.  I wonder if there is not some way
we can use numpy's build in broadcasting to make this easier. My
thinking is something like this:  1) lil_matrix.__setitem__()
figures out what the equivalent shape of the region being
assigned to is. Perhaps some numpy routines exist that can help
here?   lil_mat[1,:] -> (1, lil_mat.shape[1]) lil_mat[[0,1,2],
[5,6,7]] -> (3,) lil_mat[ix_([0,1,2], [5,6,7])] -> (3,3)  2) get
numpy to broadcast the value being set to that shape  3) use a
single code path that knows how to handle assignation from 2D or
1D arrays.  Does this make sense?   More information about the
Scipy-dev mailing list