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I agree with Geoff!  Most of my navigation programming these days is done in
C or Awk or Perl.  But unfortunately none of these little calculators runs C
or Awk or Perl.  However, I am considering moving to a PocketPC which DOES
use C and then I can have a small portable device that will have a good
programming
language.

I, like Geoff, have been programming for recreation and for my career for
25 years.

I like the idea of a long-term almanac, which has also been suggested, but I
have been doing it in my calculator and trying to reduce the formulas for a
long term almanac to a single page, rather than a whole book of tables, so
that
I can program any device in an hour to deliver a long-term almanac.

I have done just that -- I have an Awk program that implements the
coordinates
of the Sun to 0.01 degrees accuracy (using Meeus of course), and the whole
program
which delivers altitude and azimuth is easily printed on one page of paper.

Dan

-----Original Message-----
From  Geoff Kuenning [mailto:geoff@cs.hmc.edu]
Sent: Saturday, December 09, 2000 3:15 AM
To: danallen@nwlink.com
Cc: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
Subject: Re: [NAV-L] Calculators revisited (TI-86, HP 48gx)


I heartily agree with Dan in general, but my experience leads me to
one caveat.

Back before computers were affordable to the common man, I did a *lot*
of programming on my trusty new HP-41C (which is now my trusty OLD
41C).  I have found that, at least for my mind, RPN is the perfect
notation for ad-hoc calculations, but it is much less handy for
writing complicated programs.  The problem is that when you are
writing a long program, it is very difficult to keep track of what is
on the stack.  When I wrote for the 41C, I would often use a piece of
scratch paper to keep track of the stack layout.  Nowadays when I
write Postscript (see, for example, the Postscript plotting sheet
available from my Web site) I often use comments to keep track of the
stack.

I don't have same problem when writing code in languages like C and
C++, where the notation is algebraic.

My conclusion is that (for me) RPN is best for ad-hoc calculations,
but algebraic notations are more convenient for programming.

I also suppose I should mentionk, for what it's worth, that
programming is both my profession and my life (and has been for over
30 years).  Not intended as a brag, just an indication of my mindset.
YMMV.
--
    Geoff Kuenning   geoff@cs.hmc.edu   http://www.cs.hmc.edu/~geoff/

The most exciting phrase to hear in science, the one that heralds new
discoveries, is not "Eureka!" (I found it!) but "That's funny ..."
                -- Isaac Asimov

   

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