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Hi All,
     I finally got my slope-fit spreadsheet running.
I am attaching two versions since the problem
I ran unto was one of 'libreoffice calc' vs 'excel'
and they both (slope-fit.ods & slope-fit.xls) work now.
I think  Frank mentioned a certain natural error that is
unique to each person taking a sight - so I added what
I think is a neat feature: a error band that parallels the
Hc slope by +/- whatever you set the error band to; I think
of it as kind of a 1sigma, 2sigma, etc., etc., indicator.
I hope to use this spreadsheet as a tool to improve my
sight taking skills and get rid of the 'voodoo' element,
as Frank (?) put it. It should also allow me to quickly kick out
any outliers when crunching my 'actual sights' in the cabin (as opposed
to 'practice sights' on land) I am still troubled by one comment that
someone made
that "all data is good data" (?) that would imply don't worry about
outliers. Does that mean just take all data points and do a straight
average? That makes it sound like if one of your sights was 2 arc min
high, take enough sights and one will be 2 arc min low and they will
cancel. I must say I'm still struggling with the concept of 'noise' and
sights. As a radio engineer I'm familiar with 'noise' and you can even
"see it" on
the proper test equipment. There are things we do to lower it. When
taking a sight,
I would think If you do everything the same ( if know your eye height
adjusted for heel,
and always take your sight from the same place on the boat, and at the
same point
on a swell, you should minimize the noise no? Then you would only need to
find true outliers, and they should be obvious - after doing a slope-fit (?)
~Greg
(still a newbe)

   

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