How to do Curve fitting for a part of data only?

Question

I have a curve from an inverse Fourier transform. The independent variable x runs from 0 to 32 but the dependent variable y is 0 after approaximately 20x10^-3 . So I want to fit a curve only in the part where x is between 0 and 10^-3. I tried the exclude option given in curve fitting toolbox but it did not work. How do I proceed about it?

Answer 1

I would just create variables in your workspace that are in the range of interest and do the fitting with those. Something like:

x_to_fit = x(x>=0 && x<=1e-3);
y_to_fit = y(x>=0 && x<=1e-3);

Then use x_to_fit and y_to_fit in the curve fitting tool to fit your data. See http://www.mathworks.co.uk/help/curvefit/interactive-data-selection.html for more information on data selection.