Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!snorkelwacker!spdcc!ima!haddock!karl
From: karl@haddock.ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: Implementation of pow(3m) function
Keywords: math-library exponentiation C
Message-ID: <17301@haddock.ima.isc.com>
Date: 8 Aug 90 23:42:38 GMT
References: <1990Aug2.120706.25713@bnrgate.bnr.ca> <13474@smoke.BRL.MIL> <46584@brunix.UUCP> <3511@goanna.cs.rmit.oz.au>
Reply-To: karl@kelp.ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Cambridge, MA 02138-5302
Lines: 9

In article <3511@goanna.cs.rmit.oz.au> ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) writes:
>UNIX implementations of pow _do_ [special-case integer exponents].

*Some* Unix implementations do.  I have observed others in which roundoff
error causes (int)pow(2.0, 3.0) to return 7; this is an excellent reason not
to use pow() when you want integer exponentiation.  (I myself would prefer a
new operator, `*^'.  I wrote an essay on this a couple of years ago.)

Karl W. Z. Heuer (karl@kelp.ima.isc.com or ima!kelp!karl), The Walking Lint