Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!decwrl!uunet!mcsun!cernvax!chx400!ugun2b!ugsc2a!fisher
From: fisher@sc2a.unige.ch
Newsgroups: comp.binaries.ibm.pc.d
Subject: Re: Unusual program
Message-ID: <1991Jun14.123404.468@sc2a.unige.ch>
Date: 14 Jun 91 10:34:04 GMT
References: <1238@ocsmd.com>
Organization: University of Geneva, Switzerland
Lines: 26

In article <1238@ocsmd.com>, glenn@zeus.ocs.com (Glenn Ford) writes:
> I am looking for a program (or algorithm, to write my own if need be)
> that, given current time of day, latitude and longitude, will calculate
> the suns current position.  Any program or existing algorithm for this??
> If there is a more proper news group, please let me know..

Want to build a sundial, eh?

I have a program to draw a sundial on the screen and dump the coordinates
needed to draw the sundial for any size (even for declining sundials).
The problem is, of course, the equation of time.  (That is, the apparent
sun rotation is not constant over the year(s).)

I have recently posted a request to sci.astro (the proper newsgroup, BTW,
not "meteorology", as someone proposed).  An astronomer was kind enough
to send me the time equation.  This I built into the program, but in the
form of a simple table.  I would like to draw that equation on the wall
(taking for example the year 2000, it doesn't vary *that* much), but didn't
yet manage to do it.

If you would like to share info, just drop me a note.  (i.e. I'm also
interested in your info!)

good luck,

Markus G. Fischer                                  fisher@sc2a.unige.ch