Re: [Ifeffit] Jupyter/python question for Larch

Hi Matt, Thank you for the advice and speedy response! _athena_groups is exactly what I was looking for. Cheers, Garret On Tue, Aug 4, 2020 at 11:14 AM Matt Newville wrote:

Hi Garret,

On Tue, Aug 4, 2020 at 9:55 AM Garret Bland wrote:

...

Hello!

I have a Python/Larch related question. I have been developing some python script via jupyter and incorporating Larch as a module. I was able to read an athena prj file with the following code

*import larch as lc*

*athena_prj = lc.io.read_athena(prjfilename)*

Python stores this object as a 'Group' object with each spectrum being an instance. I would like to go through more processing with all spectra.

Example: *for spectrum in athena_prj:* * lc.xafs.find_e0(spectrum.energy, spectrum.mu http://spectrum.mu, group = spectrum)*

This does not work since the 'Group' object is not iterable. I tried to look up some other built-in functionality with python, but couldn't find an efficient way other than manually typing out each spectrum (athena_prj.spectrum1, athena_prj.spectrum2, .... etc). Is there any built-in functionality in larch that can iterate this 'Group' object?

Yeah, a Group is a pretty generic collection and so is not iterable. There is a dir() function, but that is not really what you want because the group returned from read_athena() contains not only the "Athena Groups" (which is what you want to loop over) but also some extra data about the project file itself. I think that what you really want is to use the (magic-ish) `_athena_groups` data in the project file group:

for spectrum_name, spectrum in athena.prj._athena_groups.items(): lc.xafs.find_e0(spectrum.energy, spectrum.mu)

or if you're just looking to extract E0 for all the groups in the project file, perhaps:

e0_vals = {name: lc.xafs.find_e0(spect) for name, spect in athena_prj._athena_groups.items()}

--Matt

PS: sorry, the word 'group' here probably has four different meanings. print(" ".join(["buffalo"]*8))!

Any help would be appreciated. Thank you for your time!

...

Garret

-- Garret Bland PhD Student Carnegie Mellon University Civil and Environmental Engineering Porter Hall 201 Pittsburgh, PA, 15213 _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

-- --Matt Newville <newville at cars.uchicago.edu> 630-252-0431 _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

-- Garret Bland PhD Student Carnegie Mellon University Civil and Environmental Engineering Porter Hall 201 Pittsburgh, PA, 15213