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From: rob@trash.whim.org (Rob Johnson)
Newsgroups: sci.math
Subject: Re: Rectangular to Polar Conversion Help
Date: Wed, 16 Jul 2003 14:18:21 +0000 (UTC)
Organization: West Hills Institute of Mathematics
Lines: 18
Message-ID: <20030715.143342@whim.org>
References: <tjhOa.15460$Ha.5367@nwrdny02.gnilink.net>
Reply-To: rob@trash.whim.org (Rob Johnson)
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In-reply-to: "N" <a@b.com>

In article <tjhOa.15460$Ha.5367@nwrdny02.gnilink.net>,
"N" <a@b.com> wrote:
>The formulas from polar to rectangular and back are this
>
>x = cos(L)* cos(B) * R
>y = sin(L) * cos(B) * R
>z = sin(B) *R
>
>then
>R = sqrt(x*x + y*y + z*z)
>B = sin-1(z/R)
>L = tan-1(y/x)

Better is L = 2*atan(y/(x+sqrt(x*x+y*y))).  This formula for L
eliminates the uncertainty as to its quadrant.

Rob Johnson
take out the trash before replying