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function av = myPolyFit(y)
%A * av = y
    n = length(y);
    y = y(:); %make `y` a column vector
   
    %construct `A`
    A = (1:n)' * ones(1,n);
    for j = n-2 :-1: 1
        A(:,j) = A(:,j) .* A(:,j+1);
    end
    A(:,n) = ones(n,1);
   
    av = A\y;

y=[22 26 20 23 24 21 20 18];
av=myPolyFit(y);
n=1:0.001:9;
val=polyval(av, n);
poly2str(av, 'n')
plot(n, val)

   0.0047619 n^7 - 0.18889 n^6 + 3.025 n^5 - 25.1806 n^4 + 116.3583 n^3
   - 293.6306 n^2 + 365.6119 n - 144

1Â¥: Originally posted by sudo at 2011-09-09 16:11:12:
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http://muchong.com/bbs/viewthread.php?tid=3573558&fpage=0&view=&highlight=&page=1

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2Â¥: Originally posted by huycwork at 2011-09-09 17:51:44:
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   1.8575e-018 n^5 - 2.8578e-017 n^4 + 1.6489e-016 n^3 - 4.2998e-016 n^2
   + 1 n - 2.0817e-016