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From: aglew@ccvaxa.UUCP
Newsgroups: comp.lang.lisp
Subject: Re: LISP floating point performance
Message-ID: <31800002@ccvaxa>
Date: Wed, 11-Mar-87 23:03:00 EST
Article-I.D.: ccvaxa.31800002
Posted: Wed Mar 11 23:03:00 1987
Date-Received: Fri, 13-Mar-87 21:57:21 EST
References: <1368@hplabsc.UUCP>
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Nf-ID: #R:hplabsc.UUCP:1368:ccvaxa:31800002:000:1954
Nf-From: ccvaxa.UUCP!aglew    Mar 11 22:03:00 1987


>I think most people who want to do good floating point would tend to
>want to code the numerical part in C or FORTRAN, or, better yet,
>use an existing FORTRAN library, like IMSL, where they don't need
>to code anything at all, but simply reuse an existing library.
>The existence of good foreign function calling capabilities in
>modern Lisps makes this an attractive option to coding the entire
>application in Lisp. This allows developers to use Lisp for symbolic
>processing, which most existing implementations do well, and use
>C, FORTRAN, or a FORTRAN library for numerical code, which these
>implementations tend to stress. This would argue for improving
>foreign function calling to make it as fast and as CONSless as
>possible.
>
>Not that good floating point optimization for Lisp isn't an interesting
>problem, but, as a practical matter, there are other ways to achieve
>the same result which may be less expensive in the end.
>
>		Jim Kempf	kempf@hplabs.hp.com

Using foreign functions as an excuse for not providing efficient floating
in LISP is a cop-out. Reusing existing code is fine - but if you're writing
a new numeric algorithm (and not all numeric analysis was finished by
the 60s) it would be nice to use a decent language, with decent macro
facilities, and the ability to manipulate the program as data. I mean,
have you ever tried to develop a generic interface to integration routines
that work over arbitrary regions in N-space? Mathematical notation was
invented to simplify thinking - it would be nice if I didn't have to
know the 10 billion names of integrate in IMSL, but could have the language
choose them for me (perhaps after asking me a few questions about the
data).

To be fair, Jim Kempf wasn't saying this - but I've sat in on conversations
where it has been said.

Andy "Krazy" Glew. Gould CSD-Urbana.    USEnet:  ihnp4!uiucdcs!ccvaxa!aglew
1101 E. University, Urbana, IL 61801    ARPAnet: aglew@gswd-vms.arpa