[SciPy-dev] matlab5 sparse IO

[Stefan van der Walt]

On Wed, Jan 02, 2008 at 03:58:58PM -0800, Matthew Brett wrote:
> Hi Nathan,
> 
> > I noticed that the Matlab4 sparse writer was a little slow, so I sped
> > it up using the coo_matrix format.  Anyway, I was going to do the same
> > for the Matlab5 writer, but it seems to be broken.  It appears that
> > the V5 code was a copy/paste of the V4 method, which it shouldn't be.
> > http://projects.scipy.org/scipy/scipy/browser/trunk/scipy/io/matlab/mio5.py#L662
> 
> I'm sorry - this was my fault - I did most of the initial rewrite of
> the code, but haven't been paying it enough attention since then - so
> thanks for your reminder.
> 
> > I don't fully understand all the magic in the matlab IO code, but I'd
> > be happy to help whomever maintains it in adding sparse V5 support.
> 
> Thanks - I am sure that will be useful.  At the moment I'm trying to
> recover from flu, and porting the scipy tests over to nose, an
> intriguing combination.  But it would be good to get onto this soon.
> 
> Will anyone else have time to join in here?  Stefan?

Sure, I can take a look tomorrow morning.

To find the "more fundamental" issues Nathan referred to, I'll take a look at 

http://www.mathworks.com/access/helpdesk/help/pdf_doc/matlab/matfile_format.pdf

Please let me know if there are any other relevant docs.  I assume the
reader functions correctly, since the unit tests pass and I see

testsparse_6.1_SOL2.mat
testsparse_6.5.1_GLNX86.mat
testsparse_7.1_GLNX86.mat
testsparsecomplex_6.1_SOL2.mat
testsparsecomplex_6.5.1_GLNX86.mat
testsparsecomplex_7.1_GLNX86.mat

in the test directory.

Regards
Stéfan