This page offers options to allow you to specify variables and parameters for the fitting function. After the settings done in this page, you could go further to the next several pages to write fitting function body, fix parameters, write initialization codes etc.
When the function model is set to Explicit:
Note that each peak function parameter has a special Peak Attribute that needs to be set on the next page. The first parameter in the parameter list must be named as "y0" and should be assigned the peak attribute "Offset/Baseline". Besides "y0", you need to define at least three more parameters, and set peak attribute as "X Center", "X Width" or "Amplitude/Area". The following is an example of a peak fitting function:
When the function model is set to Implicit:
You can also add, rename or delete the Parameters and Constants in the next setting page (the Function Body Page), see the tips at the end of the The Function Body Page.