[fitobject,gof,output] = fit(x,y,fitType

,options)

This function in MATLAB fits a model to a set of data points (x,y) using the specified fitType and options. The output is a fitted object (fitobject) which describes the model, a goodness-of-fit structure (gof) which contains statistics about the fit, and an output structure (output) which contains additional information about the fitting process.

The input arguments are:
- x: a vector of x-values representing the independent variable
- y: a vector of y-values representing the dependent variable
- fitType: a string or function handle specifying the type of model to fit (e.g. 'linear', 'poly2', @(a,b,c) a*exp(b*x)+c)
- options: an optional set of options for the fitting process, specified as a structure created using the fitoptions function

The output arguments are:
- fitobject: a structure containing the fitted model, including coefficients and other parameters
- gof: a structure containing goodness-of-fit statistics, such as R-squared and mean squared error
- output: a structure containing additional information about the fitting process, such as convergence status and number of iterations