How can I use MATLAB for curve fitting and generating an equation for g(f)?

[coffeem]

Homework Statement

Hi, I am a second year University student in the UK. I am trying to plan my labs and as part of this am trying to work out how I use MATLAB to do some curve fitting. What I wish to do is to get some points and for MATLAB to find me an equation of this curve to a reasonable degree of accuracy. I then need to square this function and finally to integrate it over some limits.

However I have looked up how to do this in a couple of books in my university library and have so far been unable to complete even the first part of this task. In the books which I found on this I am told to use the 'Basic Fitting' function. However the version of MATLAB which I have only has the Curve fitting tool, which does not appear to give me an equation but merely draws a pretty line for me, after around three hours of playing around this is getting somewhat tiresome.

Note - the sample data which I have been trying to use can be downloaded from: http://www.nottingham.ac.uk/~ppzwm/downloadsindex.htm and clicking on the g_of_f.mat link under the Johnson Noise heading. I need to generate the function of g(f). However I would rather that you told me how to do this rather than just providing me with the answer as I have to do this again independently.

Thanks

 

[coffeem]

Hey can someone please give me some pointers for this. I need to have this figured out by tomorrow.