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    Re: Nautical Almanac
    From: Robert Pearson
    Date: 2016 Jul 19, 01:26 -0700


    When I saw the Dec 1, 2014 date on the 1st page I thought this version (linked to in your post) would have the rounding error that give positive values for angle that are actually negative angles and have a 0 degree as the whole degree part. This error was corrected in an update to the Pyalmanac software package last Sept 2015.  However I see this copy apparently was printed using the corrected software even though the creation date is clearly prior the the date of the fix. 

    Copies of the almanac and the python software package used to create it are available on Enno Rodegerdts' web site:


    When I was playing around with the Python code last year I noticed 2 rounding errors in the code. When I went back to his website I found he had already posted an updated to the Pyalmanac package.

    The other rounding error I found apparently hasn't been corrected and can be found both in the version you linked to and the current version on Enno's website. This error results in rounding to 60.+ minuites instead of 0.+. Not all that drastic but in a quick lookup an unsuspecting navigator might be pick a value 1 deg off. 1st error like this occurrs on pg 3 for sun's dec at 1800 on Fri Jan 01 2016.


    Bob Pearson

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