Centre X-Y data so that the highest value of Ys is at the centre of X. And then average the curve to fit into gaussian.

Hello, I have X-Y data of a curves (one coloumn for X and 4 columns for Y). I want to centre the Y data so that the highest value of Y gets to the centre of X. Right now the curves are haphazurd and I ant to make to symmetrical. I also want to fit the average of the curves into a gaussian profile.

Any help is greatly appreciated.

[Matt J]

I think it would be better just to fit a gaussian (e.g. using fit) to each pair (X,Y(:,i)). Then the fitted mean in each column would tell you were the maximum should be.

Answer 1

[Matt J]

Using gaussfitn from this FEX download,

https://www.mathworks.com/matlabcentral/fileexchange/69116-gaussfitn

you can do a simultaneous fit of all the columns:

[X,Y{1:4}]=readvars('X-Y.xlsx'); Y=cell2mat(Y); Y=Y(:);

t0=fminsearch( @(t)objfunc(t,X,Y)  ,zeros(1,4)  );

[~,dX,p]=objfunc(t0,X,Y);

f=@(x) p{1} + p{2}*exp( -0.5 * (x-p{3}).^2/p{4} ); %fitted Gaussian

[dX,is]=sort(dX); 
Y=Y(is);
plot(dX,Y,'x',dX,f(dX)); shg

function [fval,dX,params]=objfunc(t,X,Y)

 dX=X-t(:).'; dX=dX(:);

 [params,fval]=gaussfitn(dX,Y,[],[],[],'Display','off');


end

[Titli]

This was really helpful! Thank you!