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From: ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe)
Newsgroups: comp.lang.c
Subject: Re: In search of cbrt() ...
Keywords: Gaphics Gems, cbrt() for TC++
Message-ID: <4502@goanna.cs.rmit.oz.au>
Date: 14 Dec 90 06:09:11 GMT
References: <Dec.12.18.31.04.1990.3356@paul.rutgers.edu> <14724@smoke.brl.mil>
Organization: Comp Sci, RMIT, Melbourne, Australia
Lines: 16

In article <14724@smoke.brl.mil>, gwyn@smoke.brl.mil (Doug Gwyn) writes:
> In article <Dec.12.18.31.04.1990.3356@paul.rutgers.edu> rcruz@paul.rutgers.edu (Rafael Cruz) writes:
> >... make use of the library function cbrt().

cbrt() is part of the Berkeley math library.

> However, if all it does is extract a cube-root, it's trivial to emulate:
> 	#include <math.h>
> 	#define cubrt(x) pow(x,1.0/3.0)

That doesn't quite do the job.  cbrt(-8.0) is -2.0, but pow(-8.0, 1.0/3.0)
prints "DOMAIN error" and returns 0.0.

-- 
The Marxists have merely _interpreted_ Marxism in various ways;
the point, however, is to _change_ it.		-- R. Hochhuth.