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    Re: Calculators revisited (TI-86, HP 48gx)
    From: Dan Allen
    Date: 2000 Dec 09, 11:48 AM

    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{at}cs.hmc.edu]
    Sent: Saturday, December 09, 2000 3:15 AM
    To: danallen{at}nwlink.com
    Cc: NAVIGATION-L{at}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{at}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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