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From: AdaMagica <christ-usch.grein@t-online.de>
Newsgroups: comp.lang.ada
Subject: Re: Arctan: to use with single or with double arguments?
Date: Sat, 11 Feb 2012 02:46:02 -0800 (PST)
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Date: 2012-02-11T02:46:02-08:00
List-Id: <comp.lang.ada>

On 11 Feb., 09:53, Simon Wright <si...@pushface.org> wrote:
> Adam Beneschan <a...@irvine.com> writes:
> > Yep, the arguments to Arctan in Ada (and I believe the arguments to
> > ATAN2 in Fortran) are (Y, X).
>
> Which presents a fine opportunity for confusion when you're dealing with
> Bearing (zero at North, positive clockwise); you say Arctan (X, Y).

In this case, you always should use named associations to make the
coordinate system clear - that's what named association is for.

In code reviews, I wouldn't let Arctan (a, b) pass, but always force
Arctan (Y => ..., X => ...).

It's a severe bug to use positional association for Arctan!