How to find centroid of experimental data ?

I am using MATLAB to calculate the centroid of data which i am importing from Excel spreadsheet. However, I have to use integration to calculate centroid. I am using trapz function to calculate integration.The formula which i am using here to integrate is mentioned in image.To implement (x*dx), i am using (1/2)*(d(x^2)).

But results are not up to mark.I am mentioning the code which i am using.

    format longG;
    filename='xyz.csv';
    sheet=1;
    col1=1;            %Starting Column; Nx(charge) density Values %
    col2=(col1)+1;      %X values % 

    row1=10;     %Starting Row Number%  
    row2=20;    %Ending Row Number%

    Data=csvread(filename);  % Data File Reading%

    % Access of Columns for Charge Density & X %
    charge_density=(Data(row1:row2,col1))'; %Charge density Data in row matrix%
    x=(Data(row1:row2,col2))'; 

    max_charge_density=max(charge_density(:)); %maximum value of charge density%
    normalized_charge_density=(charge_density./max_charge_density);

    %%%%%%%%%%%%%%%%%%%%%For Double Gate FET %%%%%%%%%%%%%%%%%%%

    Tfin=2;                       %Thickness of fin % 
    normalized_x=x/Tfin;          %Normalized Distance%
    x_square=normalized_x.^2;     %square of normalized distance x%

    %%%Integration of charge density with respect to Distance%%%
    numerator=(trapz(x_square,normalized_charge_density))*(1/2);
    denominator=trapz(normalized_x,normalized_charge_density);

    %Centriod Calculation%
    centroid= (numerator/denominator);

[Image Analyst]

Unfortunately you forgot to attach 'xyz.xlsx' so no one can run your code. The first problem I see is that you're trying to put all that code inside a cell by enclosing it in braces {}. The second problem I say was that you have a period after the "end" statement at the bottom. Fix those three things and then people might try your code and try to help you. http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[Amratansh Gupta]

Changes DONE. Now you can try.