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    Re: Lunars using Bennett
    From: Dave Walden
    Date: 2008 Jul 3, 18:36 -0700

    
    George asks some quite 'to the point' questions:
    
    "Does Dave agree that a fair summary of his results would be that the
    vast majority of the calculations fall within a range of 2 minutes of
    arc?"
    
    Yes.
    
    
    "I expect that Dave Walden has been careful to avoid any interpolation
    in his automated procedure, but it would be useful to have that
    confirmed."
    
    Indeed no interpolation was done.  It is in fact, when simulating
    tabular methods, very easy to carry more precision than one realizes
    or intends.  Much can be hidden by spread sheet or computer output
    formats.  Precsion can stay with a variable even if you don't see it.
    The program contains much use of the nint (nearest integer) function.
    This is how the precision of the table is replicated.
    
    
    "...Dave could only convert the angle-error to a time-error by
    presuming some mean value for the rate, such as 30 arc-minutes per
    hour."
    
    Not quite true.  Since real ephemeris data was used, actual rates are
    available.
    
    
    "So I ask Dave to make it clear whether the end-result scatter was in
    the overall difference between cleared distance and predicted
    distance, both worked from the tables, or if it was just the scatter
    in cleared distance compared with a
    precise calculation from the astronomy."
    
    The cleared distances calculated using Bennett were compared to
    ephemeris values.  Simulating almanac precision or simulating using
    tables to calculate lunar distances from RA's and Dec's would have
    "muddied the waters".  All things are possible.  The code is there for
    the interested student.
    
    
    
    
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