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From: Emanuel Berg <embe8573@student.uu.se>
To: help-gnu-emacs@gnu.org
Subject: Re: Getting used to Calc's Radian convention
Date: Fri, 12 Sep 2014 21:15:03 +0200	[thread overview]
Message-ID: <87bnqklkg8.fsf@debian.uxu> (raw)
In-Reply-To: mailman.8731.1410504469.1147.help-gnu-emacs@gnu.org

dieter@duenenhof-wilhelm.de (H. Dieter Wilhelm) writes:

> Calc's unit convention of revolution per minute (rpm)
> is derived from the angular speed and not from a
> frequency. One does not need to type the factor of `2
> pi' when calculating, for example, the
> circumferential velocity from the radius and some
> value in rpm. So far so good.
>
> But it has the slight aesthetic drawback that now the
> velocity turns out to be in units of radians.
>
> n <- 1 rpm
> r <- 1 m
> n r -> 2 pi rad m / min
>
> Since Radian is a base unit I can only get rid of it
> when dividing by `rad'. But I think a Radian is not a
> real physical unit and wouldn't it be consistent,
> when evaluating, to assign just the value of 1 to it?
>
> What are your thoughts?

My thoughts are: What?!

What are you doing, and what are you using? (Are you
even using Emacs?)

There are two macros:

    degrees-to-radians
    radians-to-degrees

But this is simple enough for you to rewrite into
functions if you prefer that.

First thought though, why can't you just get any unit
you like by simple arithmetics?

-- 
underground experts united


       reply	other threads:[~2014-09-12 19:15 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <mailman.8731.1410504469.1147.help-gnu-emacs@gnu.org>
2014-09-12 19:15 ` Emanuel Berg [this message]
2014-09-13  2:26   ` Getting used to Calc's Radian convention jay.p.belanger
2014-09-13  5:29     ` Emanuel Berg
2014-09-13  7:43       ` H. Dieter Wilhelm
2014-09-13  7:41     ` H. Dieter Wilhelm
2014-09-12  6:47 H. Dieter Wilhelm

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