Re: [Help-gsl] sparse matrices (again)

[Andrew Makhorin <mao at gnu dot org>]

Sorry for a long time delay in my response.

> Andrew Makhorin wrote:
>> As it seems to me, it would be very useful to provide GSL at least
>> with data structures defining three most commonly used formats for
>> general sparse matrices, namely, coordinate format, compressed row
>> storage, and compressed column storage, as well as two formats for
>> sparse vectors based on compressed vector storage, and a minimal set
>> of some basic functions. This would standardize representation of
>> sparse objects within the GSL library and make it possible to use
>> such data structures on developing sparse linear algebra software
>> based on GSL.

> Thanks for the suggestions.  Sorry for the delay in replying.

> It might be feasible to add sparse matrix and vector datatypes and a
> sparse blas, without adding any specific solver algorithms (which is
> what I'd like to avoid).

> If this was added to GSL, would you want to use it in GLPK, or is it
> just something you thought would be generally useful to users of GSL?

Probably the latter rather than the former. Sparse matrix algorithms
used in GLPK are very specific and probably are not interesting for
most of the users of GSL. On the other hand, some standardization of
sparse calculations, in particular, representation of sparse objects
seems to me extremely useful. I cannot judge, however, it seems to me
that GSL might include standard data types for representing sparse
matrix, sparse graphs, as well as basic algorithms for such objects.

Thank you,

Andrew Makhorin