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    Re: Finding The Symmedian
    From: Gary LaPook
    Date: 2010 Dec 18, 17:44 -0800
    I think I made the same point at:


    http://www.fer3.com/arc/m2.aspx?i=114770&y=201012

    http://www.fer3.com/arc/m2.aspx?i=114725&y=201012

    gl


    --- On Sat, 12/18/10, John Karl <jhkarl@att.net> wrote:

    From: John Karl <jhkarl@att.net>
    Subject: [NavList] Re: Finding The Symmedian
    To: NavList@fer3.com
    Date: Saturday, December 18, 2010, 3:25 PM

    Symmedian -- smuckedian. There's no practical differences among any of these triangle "centers" that have been discussed. The symmedian is the MPP from logical inference, which is based on incomplete knowledge. Or should we rephrase that last part, saying it's based on ignorance.

    The attached plot, having a relatively large cocked hat, shows that the 0.53%/area value at the MPP is negligibly greater than any reasonable point inside the hat, which would certainly be less than 0.45%/area. That 0.08% difference is irrelevant for practical navigation.

    (Dividing the distance scale by 10 and calling these units minutes of arc, scales sigma to 7.5' and the side farthest from the MPP to 3 nm from the MPP.)

    Maybe just remembering that the symmedian is closest to the shortest hat side, and next closest to the next shortest side is all that's needed in eyeballing. I think this agrees with Herbert.

    John K
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