[SciPy-user] Bug in scipy.sparse

[Stefan van der Walt]

On Thu, Nov 01, 2007 at 06:06:29PM -0000, Olivier wrote:
> Nobody seems to care much about sparse arrays in scipy.... One reason
> why i tremendously prefer arrays over matrices is that it is extremely
> easy to multiply all the rows or columns of a matrix by a vector of
> coefficients. You just do M*V to multiply column-wise or
> M*V.reshape(-1,1) to multiply row-wise.
> 
> I hate having to create a diagonal matrix for such a simple task.
> 
> Nobody is interested in having sparse arrays in scipy?

It's not that we aren't interested, but someone has to write it.  The
sparse matrix base classes need to support dot, element-wise
multiplication and broadcasting.  Then it is a simple matter of
subclassing and overriding * to get matrix functionality.  Nathan has
really done a lot to improve the underlying engine, but the Python end
of things could do with a good refactoring.

Cheers
Stéfan