The user-define curve fitting module provides an interactive graphical interface and uses the Newton's method for estimating the parameters.
The application provides a library of functions, to which can be added any new calculated functions and their parameters.
The calculated functions can be saved as a model function in the Functions Library and reused for a different range of data, by loading the function from the library,
and recalculating its parameters to provide the best fit to the new data range.
The Graphical Interface
Aabel Interactive Graphical Interface for User-Defined Curve Fitting