Re: [dev] a suckless computer algebra system

On Fri, Nov 20, 2009 at 01:53:47PM +0000, David Tweed wrote:
> FWIW, my understanding is that the LAPACK library must have an API
> which conforms with a reference Fortran implementation, but there are
> various versions implemented in various languages (Fortran, C, CUDA,
> etc).

This is true. But the LAPACK itself is a stand-alone Fortran library;
typically it is used via things like f2c.

> As for the code "quality", I can see the code driving certain people
> on this list mad because it deliberately doesn't compute things in the
> simplest way and fewest lines in order to do things like acheive close
> to optimal cache blocking on modern multicore machines. A comparison
> of how much performance can vary depending on how it's coded can be
> glimpsed in the graphs in this paper:

This is again true, IMO. I'd say that in the sense of traditional software
engineering, the code quality of numerical software is generally terrible.

But as for validity and reliability of numerical algorithms, the thing that
really matters in this context, LAPACK is again without doubt the most
respected library. In fact, it is intriguing to follow the history of
numerical matrix algebra and the close correspondence of it with the
development of ALGOL, LINPACK, and later LAPACK.

LAPACK is also the backbone in most of the mentioned, open or closed,
software.

- Jukka.
Received on Fri Nov 20 2009 - 14:15:51 UTC