From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM,
	WEIRD_PORT autolearn=ham autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII
X-Google-Thread: 103376,587583eece659d7a
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-03-16 14:04:02 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!newsfeeds.belnet.be!news.belnet.be!newsfeed00.sul.t-online.de!newsmm00.sul.t-online.com!t-online.de!news.t-online.com!not-for-mail
From: Kai =?iso-8859-1?Q?Gl=E4sner?= <Kai.Glaesner@t-online.de>
Newsgroups: comp.lang.ada
Subject: Re: Why raises this an error? :-(
Date: Sat, 16 Mar 2002 23:01:45 +0100
Organization: T-Online
Message-ID: <3C93C0C9.14A5FC7D@t-online.de>
References: <3C93A19C.67D6E442@t-online.de> <3C93ACE5.36B3BCE2@acm.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit
X-Trace: news.t-online.com 1016316095 01 17037 z-nyT1vESEASuO 020316 22:01:35
X-Complaints-To: abuse@t-online.com
X-Sender: 320068638902-0001@t-dialin.net
X-Mailer: Mozilla 4.75 [en] (Win98; U)
X-Accept-Language: en
Xref: archiver1.google.com comp.lang.ada:21347
Date: 2002-03-16T23:01:45+01:00
List-Id: <comp.lang.ada>

Thanks for the quick Response.

The problem I have is, that the exponent is not an Integer (this was
just a test-example to find out what is wrong)

   <snip> 1.0 - (GetTemperature(The, Alt)/Temp) ** 0.2349690

Where GetTemperature() can return a value < 0.0.

But why is the value of the left operand not allowed to be negative
according to the ARM?

Jeffrey Carter wrote:
> 
> Kai Gl�sner wrote:
> >
> > This:
> >
> >     Alt_D := (-8.0/4.0) ** 2.0;
> >
> > raises this:
> >
> >     raised ADA.NUMERICS.ARGUMENT_ERROR : a-ngelfu.adb:111 instantiated
> > at a-nuelfu.ads:20
> >
> > This:
> >
> >     Alt_D := -2.0 ** 2.0;
> >
> > works fine!
> 
> Exponentiation has higher precedence than unary minus (ARM 4.5), so this
> is equivalent to
> 
> Alt_D := -(2.0 ** 2.0);
> 
> ARM A.5.1 says that Argument_Error is raised "by the exponentiation
> operator, when the value of the left operand is negative". This is the
> case in your first example.
> 
> Since your exponent is an integer value, you can avoid this restriction
> by using the predefined exponentiation operator for floating-point
> types:
> 
> Alt_D := (-8.0 / 4.0) ** 2;
> 
> --
> Jeff Carter
> "Your mother was a hamster and your father smelt of elderberries."
> Monty Python & the Holy Grail