[SciPy-user] Interaction of sparse and dense matrices in scipy

Nils Wagner nwagner at mecha.uni-stuttgart.de
Mon Feb 20 03:30:12 CST 2006

Hi all,

I need some advice on operations between dense and sparse matrix "objects".
Which operations are possible in scipy ?

Assume that A and B are sparse while C and D are dense matrices of
appropriate dimension.

dense                           sparse

dot(C,D)                      A*B
linalg.norm(C)            linalg.norm(C.todense())
linalg.kron(C,D)           ?
identity(n), eye(n)           

How about interactions of sparse and dense matrices

- multiplication of a sparse matrix A with a dense matrix C
- Kronecker product of sparse matrices ?
- Kronecker product of a dense and a sparse matrix ?
- sparse matrix functions expm(A),... ?
- sparse eigensolver
- to be continued

Can I use different sparse formats like csc and csr w.r.t. to
multiplication, addition,...

And what is the output of A = io.mmread("A.mtx") ? I mean sparse or dense.

Any comments ?

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