From: Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>
Subject: Re: Arctan: to use with single or with double arguments?
Date: Fri, 24 Sep 2010 14:55:49 -0700
Date: 2010-09-24T14:55:49-07:00 [thread overview]
Message-ID: <i7j7hm$dcv$1@tornado.tornevall.net> (raw)
In-Reply-To: <908e7aea-ed77-4dce-9f5d-e6341abc1303@s19g2000vbr.googlegroups.com>
On 09/24/2010 02:32 PM, Ada novice wrote:
>
> Now I know that Arctan(Y, X) gives the result between -pi to pi while
> Arctan(Y / X) gives the result between -pi/2 to pi/2.
There is no one-parameter Arctan defined in
Ada.Numerics.Generic_Elementary_Functions; the parameter X has a default of 1.0,
so what you're really calling is
Arctan (Y / X, 1.0);
Since the X parameter is positive, it's clear the result will be in quadrant I
or IV, or -Pi/2 to Pi/2. Giving both parameters thus seems more accurate, as it
correctly handles cases in all 4 quadrants. In addition, it is defined for X =
0.0 (except when Y = 0.0).
HTH.
--
Jeff Carter
"We use a large, vibrating egg."
Annie Hall
44
next prev parent reply other threads:[~2010-09-24 21:55 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-24 21:32 Arctan: to use with single or with double arguments? Ada novice
2010-09-24 21:55 ` Jeffrey Carter [this message]
2010-09-25 8:44 ` Ada novice
2010-09-25 17:31 ` Jeffrey Carter
2010-09-25 21:34 ` Ada novice
2010-09-26 4:02 ` jpwoodruff
2010-09-26 8:21 ` Ada novice
2010-09-26 7:31 ` Jeffrey Carter
2010-09-26 8:24 ` Ada novice
2012-02-11 0:26 ` Jack Mitchell
2012-02-11 1:11 ` Adam Beneschan
2012-02-11 8:53 ` Simon Wright
2012-02-11 10:46 ` AdaMagica
2012-02-11 15:29 ` Simon Wright
2012-02-11 16:21 ` Georg Bauhaus
2012-02-11 16:47 ` Simon Wright
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