[SciPy-Dev] 64-bit sparse matrix indices

[Pauli Virtanen]

Nathaniel Smith <njs <at> pobox.com> writes:
[clip]
> Actually on re-reading your mail, I guess the options you're suggesting are:
> 
> A: both 32- and 64-bit indices are possible, which is used depends on nnz
> B: both 32- and 64-bit indices are possible, which is used depends on
> python's architecture
> 
> ?

Precisely.

> So I withdraw the above comment -- both options require some sort of
> annoying type parametrization, it isn't really a disadvantage of
> option A.

Yep, except that in B the "type parameterization" just means using
the intp data type and can be done with a single typedef.

But I see your point, B completely breaks backward compatibility,
whereas A does not.

> (Also surely it's only a 33% memory overhead compared to now? But
> still I have the feeling people really do work with sparse matrices
> right up to the limit of their available memory.)

Yeah, this might be the case. I guess I'll try to make A to work then.
This is mostly just a matter of ensuring the test suite coverage is
good enough.

    Pauli