This menu (Fitting/Edit Custom Model in the menu bar) interface is to provide you an easy way to write your own custom models. The changes in a model function are effective after it is re-selected from the combo-box menu.
This option is used to make a new model. A model code generated by this option can be viewed and further modified by the 'Advanced' option below.
This option is used to change the p1 or p2 model in the sum model (Note: Not all models are currently supported). Select the model names in the combo box. The model name will be "UpperCaseOnly(p1_name)+UpperCaseOnly(p2_name)". It will overwrite the previous the sum model. If you need to keep the older sum model, use the 'Advanced' option to edit and save as a different file name(.py).
The menu option shows all the files in the plugin_models folder. You can edit, modify, and save it. It is recommended to modify only the lines with arrow (## <-----). In the end of edit, 'Compile' and 'Run' from the menu bar to activate or to see the model working properly.
The menu option is to delete the custom models. Just select the file name to delete.