[SciPy-user] sparse matrix formats
Travis Oliphant
oliphant at ee.byu.edu
Tue Oct 26 17:25:53 CDT 2004
David Grant wrote:
> I am a bit boggled by all these sparse matrix types in the sparse class.
>
> Can anyone recommend which are the standard one I should use (when in
> doubt)?
spmatrix is just the base class and is not functional by itself:
The formats at the top are currently best supported.
csc_matrix --- used internally by lot's of routines, best for numerics
but can be slow to construct using Python indexing
csr_matrix --- nearly as fast as csc_matrix and useful for fast
transpose operations.
dok_matrix --- fast construction in Python (just a simple dictionary),
but must be converted to csc_matrix for fast matrix multiplication, etc.
I hope this helps,
The documentation is lacking for Sparse, but the code should be fairly
readable. Just ignore all but csc_matrix, csr_matrix, and dok_matrix
for now.
There are some bugs in dok_matrix and in mixed csc csr matrix
multiplication in SciPy 0.3.2 that have been fixed in CVS.
-Travis
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