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

[Andrew Makhorin]

>> I am wondering if it is planned to eventually provide GSL with general
>> sparse matrix routines (e.g. like those ones which are included in NAG,
>> ESSL, or Harwell Library)?

> So far we haven't added sparse matrices because it seemed like
> this would require several sparse matrix representations to be
> implemented in order to be useful, each with their own functions.

> Due to the potentially large amount of work involved, it seemed
> like this was best left to specialised sparse matrix packages.
> As I understand it the number of sparse functions in the NAG
> library is pretty big.

> If you have any suggestions in this area I'd be glad to hear
> them.

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.

Thank you,

Andrew Makhorin