Hi Matt,
Thanks for your detailed instructions. I am just trying to follow the steps and see how it works. I am not trying to do complicated things.
My issue is I would expect the grey vertical lines after press the "Fit Baseline" button, but nothing shows up. I tried to select a larger region(which was not pre-peak), also nothing happened. So I am confused.
From what I saw of your screenshot (not much to go on, really), it was not obvious that your data has much (possibly "any") pre-edge data. It also shows as "scaled y" vs "x", which suggests that the data wasn't even read in as XAS data.
Besides, can I use the XAS Viewer to do main peak fitting?
Well, I guess another way to put that is: yes, you probably can use XAS Viewer to do general-purpose peak-fitting. It is not really designed for that, but you might be able to make that work. If that is what you want to do. Is that what you are trying to do?
I know that Larch has its own language based on python. I am wondering can I use larch function, like fitting peaks in Jupiter Notebook?
You can use larch as a Python library, or use the lmfit Python library to do the fitting. Some Larch functionality, notably the plotting and GUI aspects, may not work well from a Jupyter notebook.
If you're using Python or Jupyter notebook, you probably don't really need to use the Larch language for most XAS processing and analysis functionality.
Hope that helps,
--Matt
PS: I should say that if one is really doing Feff-based fitting with `feffit()`, it is still really, really helpful to create a `larch.Interpreter()` and pass that around to all of the corresponding functions. Over the past year or so, this requirement has been removed from most of the Larch functions but the functions for doing Feff-based fitting are more intertwined and so keep some "state information" within a "session". But that seems separate from the question here.