MATLAB: Calculating Kernel density for each column

MATLAB

Hi
Please how do I need a short code that will calculate the KDE of each column in the R.length data below
the KDE is given as = I/n*h sum ( K * (( v – i )/h) which is computed for each column
where h = 1.06 * variance * (n^(-0.2)) for each colum
n is the number of each column
i = first, second, third, fourth, fifth, sixth number of each column
v =pv is given as 3, 4, 5, 6 for each column
Thanks in advance
jonathan
R = [ 0.6164 3.4161 0.9950 3.4117;
3.1654 0.4123 4.2391 1.0198;
0.5745 3.0364 1.3191 3.1129;
2.9883 0.7348 3.8730 0.4123;
0.9381 3.3749 2.0421 3.5014;
2.1817 1.0630 3.0643 0.9487];

Best Answer

I am assuming the v values are the same as the column index, and that you made a mistake with the code for the second column.
Z =  [ 0.6164    3.4161    0.9950    3.4117;
    3.1654    0.4123    4.2391    1.0198;
    0.5745    3.0364    1.3191    3.1129;
    2.9883    0.7348    3.8730    0.4123;
    0.9381    3.3749    2.0421    3.5014;
    2.1817    1.0630    3.0643    0.9487];
n = 6;
K = 3;
z=zeros(1,size(Z,2));e=zeros(size(z));
for col=1:size(Z,2)
    v=col;%is this what you mean?
    h = 1.06 * var(Z(:,col)) * (n ^ 0.2);
    z(col) = 1/ (n * h);
    E   = K * (v - Z(:,col))/h;
    if col~=1
        %did you mean for this to be different?
        E(1)= K * (v - Z(1,col)/h);
    end
    e(col) = sum(E) ;
end
% the kernal density estimation
KDE = e .* z;
Related Question