Path: utzoo!utgpu!water!watmath!clyde!rutgers!mit-eddie!uw-beaver!cornell!rochester!ur-tut!sunybcs!boulder!hao!ames!amdcad!sun!quintus!ok
From: ok@quintus.UUCP (Richard A. O'Keefe)
Newsgroups: comp.lang.c
Subject: Re: Power operator?
Summary: ambiguity
Message-ID: <516@goedel.quintus.UUCP>
Date: 9 Jan 88 03:47:31 GMT
References: <11169@brl-adm.ARPA> <10026@ut-sally.UUCP>
Organization: Quintus Computer Systems, Mountain View, CA
Lines: 15

There are two power operators:
	<any> ** double -> double	/* pow() */
and	<any> ** int -> double		/* rtp() -- MISSING */
A quick check though a couple of books of statistical algorithms in
Fortran showed me that <expr> ** k for k an integer known at compile
time appeared roughly once each in fewer than 10% of the functions.
The equivalent of pow() was even rarer.  Having to write rtp(X, 3)
instead of X**3 doesn't seem like such a big deal to me.  It's not
that common.  What irks me is having to write my own rtp().  I know
how to do it, but it's not as fast as the vendor could provide, and
the vendor-provided one might even do IEEE-854-sensible things.

Just to make it clear that pow() is not what is wanted:
	rtp(-2.0, 3) is -8.0
	pow(-2.0, 3.0) involves taking the logarithm of -2.0 ...