Date: Tue, 4 Aug 1998 20:27:54 GMT
Reply-To: Melvin Klassen <Klassen@UVIC.CA>
Sender: "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From: Melvin Klassen <Klassen@UVIC.CA>
Organization: University of Victoria
Subject: Re: SASTrap: Use of ** operator can be inconsistent
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On Tue, 4 Aug 1998 19:17:34, email@example.com (Walter Davis)
> but there is an oddity, or inconsistency, or trap, or something
> regarding negatives raised to powers less than 1.
> For example, the cube root of -1 is -1 (yes, there are more exciting examples
> Yet SAS won't properly evaluate it.
> Not that this comes up in practice for me very often.
The "trap" is that SAS evaluates 'X**Y' by using 'EXP(Y*LOG(X))'.
Note that this algorithm restricts the value of 'X' to be a positive