From: rtr AT rd DOT bbc DOT co DOT uk (Richard Russell)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Curious floating point exception errors
Date: 5 Sep 1997 13:38:33 GMT
Organization: British Broadcasting Corporation, UK
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firewind (firewind AT metroid DOT dyn DOT ml DOT org) wrote:
: This post is off-topic for comp.os.msdos.djgpp. Next time, try posting to
: alt.mindreading.programmers, or actually including the problem code.

Thanks to all those who helped (rather than making facetious comments:
there would have been no point including the source code as there was over
50K of it, and almost any change - such as trying to isolate the faulty
section - caused the problem to go away).

The problem was, indeed, an uninitialised array as I and most of those who
made helpful comments had guessed.  The reason it had gone undetected was 
that (for historical reasons) the initial contents of the array were always
multiplied by zero.  Hence any valid number (except infinity) in the
uninitialised array was OK, but invalid numbers triggered an exception.

Richard.