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    Re: Haversines with Logarithms
    From: Frank Reed
    Date: 2020 Oct 10, 18:21 -0700

    Hello Matt.

    Welcome aboard. Your tables have posted safely. Please note I converted the original docx file to pdf because the docx crashed at least two viewers.

    I'm not sure you needed to "name" your tables. You can call them whatever you like, of course and as you wish, but it's not likely that any other navigators will play along unless your name for your tables offers some benefit. Maybe of greater concern, I hope you understand that tables of haversines are trivial to create from scratch with modern tools. I timed myself constructing one this afternoon to reproduce yours. I gave myself ten minutes to make a spreadsheet that could display haversines and log haversines for some short range of angles in a "clean" format as a demo. That was enough time. See attached. You need a hook, something that sets your tables apart!

    Maybe you have a hook already. You have caught my curiosity with your logarithm values. I can see that they are logarithms, but they're "funny". Can you explain how you calculated them? When I generate standard logs as 10+log[hav(x)], I get numbers that are linearly related to yours. That means yours are behaving as I would expect logarithms to behave. And that's good! But I don't see where the actual log numbers are coming from in your table... 

    When you messaged earlier today, you said you wanted these tables to be available to a wider audience. And I just want to assure you that NavList is the right place for that. You files are now part of the NavList archives which constitute one of the largest and longest-running collections of navigation resources available anywhere. Further, there are quite a few NavList members who get a kick out, salivate over, even obsess over haversine calculations and haversine tables. I do suggest that you post a follow-up message maybe explaining how you got into this. I'm sure you'll get some replies from fellow haversonians. 

    Frank Reed

    File:
    quick-hav-table.pdf
       
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