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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: The Darn Old Cocked Hat  the sequel 1
From: Gary LaPook
Date: 2013 Mar 13, 23:33 0700
From: Gary LaPook
Date: 2013 Mar 13, 23:33 0700
I don't see how you get the hole in the center of your graphic. Look at the table of probabilities versus standard deviation. http://fer3.com/arc/img/114399.extended%20table%20q7d.pdf Using the numbers from that table I calculated the areas of each annulus and each ring has a greater area than the next smaller ring. The second attached graphic shows the areas of each annulus in square standard deviation units. Since each ring has a 10% probability (except for the outer ring which has only 9.9%) each ring will contain 10% of the fixes or 10 if using a total of 100 fixes. So dividing 10 by the area of each ring we can find the density of fixes per unit area. Since the center circle has a smaller area than any of the other rings the density of fixes in the center is greater than further out so no hole in the center. The area of the central 10% ring is 0.66 so the density is 15.1 per square standard deviation unit. The 20% ring has an area of 0.74 so the density is down to 13.5 and the density gets less and less until the last 9.9% has a density of only 0.3. gl  On Tue, 3/12/13, Hanno Ix <hannoix.net> wrote:
