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From: rob@raksha.eng.ohio-state.edu (Rob Carriere)
Newsgroups: comp.lang.c
Subject: Re: "Numerical Recipes in C" is nonportable code
Message-ID: <554@accelerator.eng.ohio-state.edu>
Date: 1 Sep 88 03:48:49 GMT
References: <664@lindy.Stanford.EDU> <6758@megaron.arizona.edu> <718@gtx.com> <13258@mimsy.UUCP> <531@accelerator.eng.ohio-state.edu> <1673@dataio.Data-IO.COM> <547@accelerator.eng.ohio-state.edu> <8400@smoke.ARPA>
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Reply-To: rob@raksha.eng.ohio-state.edu (Rob Carriere)
Organization: Ohio State Univ, College of Engineering
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In article <8400@smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
>In article <547@accelerator.eng.ohio-state.edu> rob@kaa.eng.ohio-state.edu 
>(Rob Carriere) writes:
>>The problem is that the authors of Numerical Recipes (NR) observe,
>>correctly, that many numerical problems are naturally non-zero based.
                       ^^^^^^^^^^^^^^^^^^
>INcorrectly!  I've written a lot of array/matrix code in both
                                     ^^^^^^^^^^^^^^^^^
>Fortran and C, and have found that it normally doesn't matter
>and in those cases where it does matter, it doesn't matter much.

Trivial refutation time!  Surely it is obvious that ``numerical
problems'' forms a (large) superset of ``array/matrix code'' as far as
numerical analysis is concerned?

Believe it or not, but there are *many* algorithms out there where
it's either base-1 indexing or index arithmatic all over the place.
Not with your traditional LU-decomposition stuff and so on, but with
algorithms where the contents or properties of the matrix elements are
computed from the indeces.

Rob Carriere