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Re: comparisons between floats and ratios
- To: Richard Fateman <email@example.com>
- Subject: Re: comparisons between floats and ratios
- From: David A. Moon <Moon@SCRC-STONY-BROOK.ARPA>
- Date: Sun, 26 Jan 86 16:24 EST
- Cc: common-lisp@SU-AI.ARPA
- In-reply-to: <8601250500.AA05647@dali.berkeley.edu>
Date: Fri, 24 Jan 86 21:00:53 PST
From: firstname.lastname@example.org (Richard Fateman)
I remain unconvinced, and a private note from Cassels also didn't
help. (My mailing system was unable to send to Cassels individually,
so here is a simplified response )
consider (/ (expt 10 68) 1.0E38) .
The numerator overflows when you convert to floating point.
The quotient is representable. I think that CL should err on the
side of slow&correct.
How is this example different from (/ (* 1.0e34 1.0e34) 1.0E38) ?
If you want to campaign against the widespread misimpression that floating
point is foolproof way to do numerical calculations, that's a fine thing, but
I think this is the wrong mailing list.