Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Averaging
    From: Herbert Prinz
    Date: 2004 Nov 5, 05:07 -0500

    Alexandre Eremenko wrote:
    
    > Just do it. You want to find the line y=ax+b of the best fit
    > say from 3 observations
    > (x_1,y_1), (x_2,y_2), (x_3,y_3).
    
    I want nothing of the sort. As I said, my equation M * x = a refers to any
    system of linear equations.  In the problem in hand, these represent LOPs
    and the solution of the system is the FIX. I said it is wrong to go the
    roundabout way via an intermediate set of best fitted lines (be they
    straight or otherwise). But I said that several times already.
    
    
    > Just do the "least square procedure" as you described, and find a and b.
    > Then compute the averages x=(x_1+x_2+x_2)/3
    > and y=(y_1+y_2+y_3)/3.And then plug the averages to the equation y=ax+b.
    > If you do all your computations correctly, you will see that they fit:-)
    
    > So the "method" you propose, in the case of a linear function,
    > gives EXACTLY the same answer as simple averaging.
    
    Have you actually looked at the algorithm in the N.A.? Have you looked at
    the articles in the Navigation Journal? That's what I am proposing. How can
    you believe that I want to solve a linear regression, when I said in several
    messages to its proponents that this is the wrong way to go about it?
    
    Herbert Prinz
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site