[Matrix-SIG] Re: Matrix-SIG digest, Vol 1 #215 - 4 msgs

[Henk Jansen]

On Fri, 21 May 1999, you wrote:
> Message: 2
> From: turner@blueskystudios.com (John Turner)
> Date: Thu, 20 May 1999 10:22:28 -0400 (EDT)
> To: matrix-sig@python.org
> Subject: Re: [Matrix-SIG] Sparse objects
> 
> >>>>> "HJ" == Henk Jansen <hjansen@math.tudelft.nl> writes:
> 
> HJ> In the "old" Fortran days, I did some work using Yousef Saad's
> HJ> SPARSEKIT (2) sparse matrix (source) library. He was supporting
> HJ> most (appr. 10) of the formats most commonly used. They were all
> HJ> pretty well described in the documentation. It may pay off having
> HJ> a look at it. (I think it's available on Netlib).
> 
> But if I recall correctly, SPARSEKIT was one of the "researchy" pkgs I 
> alluded to in my previous msg that really only supported one format
> internally (compressed sparse row, CSR, if I remember correctly), and 
> accomodated other formats by providing routines to convert to and from 
> CSR.

Yes, you're right, they only supported CSR and conversion routines to and from
it. I never realized (or, can't see) that "production" code would require full
(solver) support for all formats. Sparse objects by their nature are lean and
quickly convert into other (sparse) objects. Is that penalty too high?

> 
> Fine for investigating algorithm performance, developing solvers and
> preconditioners, etc, but not for "production".

Henk. 

 -Henk Jansen - hjansen@math.tudelft.nl - phone/fax +31(0)15-278-7295/7209-
 --Dept. of Mathematics and Computer Science - Delft University of Technology-
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