[ESSDIFFRACTION, BEER] Add Q coordinate in Sciline workflow

[celinedurniak]

In addition to d-spacing, wavelelength, we'd like to have Q as an additional coordinate in the data array.

[jokasimr]

You can always add Q to the event data at a later point using:

iof_dspacing.transform_coords('Q', graph=workflow.compute(ElasticCoordTransformGraph[SampleRun]))

or similar.

I don't think its preferable to add it directly to the workflow because that will use more memory.

But if the above solution is insufficient, tell me and we can figure out a solution.

[SimonHeybrock]

We could also add additional leaf nodes in the graph that are not in the main path that do this (maybe similar in #744). No downside for the "production" workflow, but more convenient for manual use.

[jokasimr]

That's a good point. Would you prefer that @celinedurniak ?

[celinedurniak]

I need a bit more details.
What do you mean by "leaf nodes"?
What would the user see and be able to do if this is implemented?

[SimonHeybrock]

I would mean that you would run sth. like workflow.compute(AugmentedRawDetector) (naming up for discussion) instead of workflow.compute(RawDetector). AugmentedRawDetector could be a DataArray containing the extra coords you are looking for.

[celinedurniak]

Thanks for the explanations.
It would work if RawDetector contains for example d-spacing and AugmentedRawDetector contains d-spacing, Q and other coordinates for "external" processing

[jokasimr]

1. RawDetector is supposed to be "raw" in the sense that it does not contain derived coordinates, but only the raw data that is read from the file. WavelengthDetector additionally contains the wavelength data. DspacingDetector additionally contains dspacing, and CorrectedDetector additionally contains masks and some correction factors like lorentz correction.
2. In this case I guess what would make most sense is adding a QDetector that would directly depend on DspacingDetector. Would that work for you @celinedurniak ?

[celinedurniak]

I prefer the idea to have more coordinates available in a single dataarray: the augmented version

[jokasimr]

In the example I gave above QDetector would have all cords that DspacingDetector has, and it would additionally have Q. Just like DspacingDetector also has all coordinates that WavelengthDetector has. So in essence it would be the AugmentedDetector mentioned above.

[celinedurniak]

OK. This would work.