curve fitting in MATLAB by using curve fitting tool

I have a data that should fit a gaussian into it and then finding the center frequency and sigma, I use curve fitting tool in the matlab for this goal. Now in the curve fitting tool there is an option "center and scale", highlighted in yellow in the image below. If I chose this option the results will bedifferent than not chosong this option. I dont know what is this "center and scale" and which one the results are the ones I want.

Answer 1

[Matt J]

The centering/scaling means the xdata,ydata will be pre-normalized before any fitting is done. The doc is not specific about what the normalization is, but likely it is something like

xdata=(xdata-mean(xdata))/std(xdata)
ydata=(ydata-mean(ydata))/std(ydata)

As for which one you want, you want the one that gives the better fit. Look at the results and take the one that is better.

[2NOR_Kh]

Thank you so much,

I have another question, I should fit Burr distiribution to another data but matlab curve fitting does not have this distribution, in this curver fitting tool do you know that I can add a distribution or not?

[Matt J]

Thank you so much,

You are quite welcome, but please Accept-click the answer to indicate that your question has been addressed.

I should fit Burr distiribution to another data but matlab curve fitting does not have this distribution, in this curver fitting tool do you know that I can add a distribution or not?

You can define custom curve models:

https://www.mathworks.com/help/curvefit/custom-nonlinear-models.html

When you do, however, it is usually important to supply a good initial guess of the parameters.

[Walter Roberson]

Center and Scale affects X but not Y.