curve fitting toolbox code

Hi everybody

I fitted my curve which goes over these two points(0,0) and(1,1) in matlab fitting toolbox, i want to extract what will be the y if x=2 in m.file.

How to convert toolbox to code and create function in which when I import x=2 it shows y=2 .

I don't know why the generation code is a function of x & y not only x.

Can anybody help me?

thanks

[dpb]

You save the fit object and then simply call it with the input variables as a function.

See the documentation for all the details; you'll probably find the "Postprocessing" part of most use for these questions once have a model.

[saeed]

thanks for your reply but as i didn't understand what you said I make my question clear:

these are my point:

x=[1 2]

y=[2 4]

I open cftool, select x for xdata and y for ydata, then from the fit menu I click on "save to workspace" and save the 3 fits, now if I type fittedmodel(3) in the command section, it shows output=6, but if I close matlab then it doesn't show output 6, what should I do to call fittedmodel(3) from another m.file?

thanks

[dpb]

You have to somehow get the fit object into the correct context; functions have their own context and so a new function doesn't know anything about the model you saved into the workspace.

Three basic options --

1. If you have the data available, build the model from the data in the function having used the fit tool to find the class of model that is satisfactory, or;
2. SAVE the fit object you created in the fit tool to a .mat file and load it back within the function, or
3. pass the object to the function from a context in which it does exist.

The tool can also build an m-file which will regenerate the model but it also either must read in the data again or have it stored internally.