# Library hierarchy, contd.

**Simon Marlow
**
simonmar@microsoft.com

*Fri, 25 May 2001 10:12:11 +0100*

>* Dylan mentions "matrix classes" and then concludes:
*>*=20
*>* > Maybe "Computational" would be a better name than "Numeric"?
*>*=20
*>* I've been trying to demonstrate that there more to=20
*>* "matrix" than just data structure or just simple linear=20
*>* equation solver. It is easy to come up with the latter,=20
*>* or with a set of primitive product operations. But people=20
*>* seem to be ignoring the fact that there is much more to linear
*>* algebra than those trivialities. Eigenproblems for
*>* example... Dense cases, sparse cases and all that Pandorra
*>* box of non-trivial engineering tools.=20
*>*=20
*>* These things are still alive, thank you very much, and=20
*>* the papers are still written about them every day. Neither
*>* the problems nor the papers are trivial.
*>* =20
*>* Yet they are being ignored in your hierarchy.
*>* Please, mark at least some spot for them. And do not tie them=20
*>* to "matrix" because "matrix" is just one specific representation
*>* of operator algebra -- as I am showing in some modules
*>* of mine, for example.
*>* I do not care what name you choose. Computational?
*>* Linear algebra? But please do not ignore them altogether.
*
We're not ignoring these issues, sorry if you got that impression. I'd
certainly like to see a suggestion (better still, a proposal) for
organising these libraries from people such as yourself and Dylan.
Cheers,
Simon