nlinfit for a function of 2 variables

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Roy Elbaz
Roy Elbaz on 29 Aug 2017
Answered: Star Strider on 29 Aug 2017
Hey,
I want to get a Gaussian git for my data using Matlab. However, I'm expecting a 2D Gaussian - Z(x,y)=A*exp(-(x^2+y^2)/2σ^2) Is there a way of using nlinfit for this?
I saw another question here about nlinfit for a 2 variables function, however in that function they weren't coordinates. I need all the combinations of X and Y in order to make the fit.
loc=[XC YC];
gaussian = @(param,x) param(1)*exp( -((x(:,1)-param(2)).^2+(x(:,2)-param(3)).^2+)./(2*param(4).^2) ) + param(5);
params=zeros(1,5);
params(1)=A*maxVal;
params(2)=maxXpos;
params(3)=maxYpos;
params(4)=estW;
params(5)=nPixInf(1,1);
paramsX = nlinfit( loc , nPixInf , gaussian , params );
XC and YC are just 2 one dimensional arrays that goes from 1 to the size of that dimension. nPixInf is a 2 dimensional matrix which suppose to look like a Gaussian.
Can I use nlinfit for this?
Thanks!

Answers (1)

Star Strider
Star Strider on 29 Aug 2017
It looks to me that you have coded your ‘gaussian’ function correctly. (I’ve used this approach successfully with nlinfit.)
Are you having problems with it?

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