//First import the desirable data into a new book
 
filename$ = system.path.program$ + "Samples\Curve Fitting\Gaussian.dat";
 
newbook;
 
impASC filename$;
 
//Use the NLSF class to create a GUI tree "nlGUI"
tree nlGUI;
xop execute:=init classname:=FitNL iotrgui:=nlGUI;
 
//Specify function and input data, then update operation tree before fitting.
 
nlGUI.GUI.FunctionSelection.FunctionList$="Gauss";

nlGUI.GUI.FunctionSelection.fitmethod=1; //Use ODR
 
nlGUI.GUI.InputData.Range1.X$=Col(A);
 
nlGUI.GUI.InputData.Range1.Y$=Col(B);


xop execute:=update iotrgui:=nlGUI;

xop execute:=report iotrgui:=nlGUI;
 
//Clean up operation objects after fit
 
xop execute:=cleanup;