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    Re: Lat/Lon by "Noon Sun" & The Noon Fix PROVE IT
    From: Hewitt Schlereth
    Date: 2009 Apr 23, 20:46 -0400

    Thanks, Fred and Peter -
    
    I remember when Frank started a tutorial on spreadsheets a while ago.
    I went to OpenOffice and found there was no version for my Mac
    operating system. I also remember I got befuddled quite early on.
    
    I'll check AppleWorks to see what I can discoveer.
    
    Hewitt
    
    On 4/23/09, P H  wrote:
    >
    > Try OpenOffice or NeoOffice.    Peter
    >
    > ________________________________
    > From: Hewitt Schlereth 
    > To: NavList@fer3.com
    > Sent: Thursday, April 23, 2009 2:59:27 PM
    > Subject: [NavList 8027] Re: Lat/Lon by "Noon Sun" & The Noon Fix PROVE IT
    >
    >
    > George, I have a Mac iBook and it doesn't have a spread-sheet program.
    > Pressing F9 does absolutely nothing.
    >
    > The AppleWorks program did open your "long around noon.xls"
    > attachment. What I was presented with  looked much like a ledger page.
    >
    > The altitudes I used for figuring longitude were from the "perturbed
    > alt" row on that page. They were nearly equal - i.e.,10.812 at 1210,
    > 10.815 at 1250.
    >
    > The altitude for latitude was from the same "perturbed alt" row -
    > 10.914 at 1230.
    >
    > Hewitt
    >
    > On 4/23/09, George Huxtable  wrote:
    > > Hewitt Schlereth wrote-
    > >
    > >
    > >  | George, it looks like I may have misunderstood the document I got the
    > >  | (nearly) equal AM/PM altitudes from. I thought it was your spreadsheet
    > >  | and cited it's designation - LONG AROUND NOON.XLS (SS) - in the
    > >  | worksheet I attached to my e-mail. The numbers I used were from that
    > >  | document - which I took to be yours. They looked mighty like sextant
    > >  | altitudes; so, certainly not random numbers generated by me.
    > >  |
    > >  | Maybe my worksheet didn't come through to the List?  Here it is again.
    > >
    > >  ==================
    > >
    > >
    > > Hewitt and I have got ourselves at cross-purposes, it seems.
    > >
    > >  I had produced 20 simulated sets of "perturbed" sextant altitudes, each
    > of
    > >  13 observations taken at regular intervals around noon. These were
    > offered
    > >  so that list-members could analyse them in any way they chose, to try to
    > >  discover the original latitudes and longitudes on which they were based,
    > >  information which I withheld. The table was attached to [7940] as
    > >
    > > noon1a.rtf, or (the same data), attached to [7959], as noon1a.doc .
    > >
    > >
    > > In case anyone wanted to see how that data had been generated, I also
    > added
    > >  the Excel spreadsheet, that generated those data sets.. Each time that
    > >  spreadsheet is run, (or when button F9 is pressed), a new set of random
    > >  numbers is generated, which creates a new, unique set of perturbed
    > >  altitudes. I hadn't intended anyone to use that spreadsheet itself to
    > >  generate those sets of altitudes, but there's nothing wrong with doing
    > so;
    > >  indeed, that's what Dave Walden did, generating 1000 such sets to look
    > for
    > >  the scatter.
    > >
    > >  Hewitt has done the same, but has generated only one such data-set, which
    > >  has given an answer which Hewitt tells is is within 1' of the intial
    > value.
    > >  To which I suggest that if that is the case, it's only so as the result
    > of a
    > >  fluke, and will not be repeatable.
    > >
    > >  If Hewitt will kindly load and run that Excel program again, it will
    > invent,
    > >  this time, a completely new set of 13 altitudes, showing a similar
    > general
    > >  shape but differing in every detail. And if he analyses the new set as he
    > >  did before, he will, I suggest, get a very different answer. Every time
    > he
    > >  presses F9, it will change again.
    > >
    > >  However, having satisfied himself on that score, he could usefully apply
    > >  whatever technique he chooses, to one or more of the data sets attached
    > to
    > >  those messages cited above, also attached here. The first two sets, only,
    > >  provide that original data. For the other 18, only I know the original
    > lat
    > >  and long from which the data set has been constructed.
    > >
    > >
    > >  George.
    > >
    > >  contact George Huxtable, at  george{at}hux.me.uk
    > >  or at +44 1865 820222 (from UK, 01865 820222)
    > >  or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    > >
    > >  >
    > >
    > >
    >
    >
    >  >
    >
    
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