Flux changes for NXmx

[phyy-nx]

• Add flux_integrated and total_flux_integrated, Useful where temporal profiles of flux are not known.
• Change total_flux to not be required
• Add NXbeam attribute flux, to point to which flux field is used
• Add optional NXmonitor for additional incident beam data

Closes #986
Closes nexusformat/NIAC#96

[yayahjb]

Good fix -- Herbert

[woutdenolf]

Referenced units:

• NX_FLUX: 1/s/cm^2
• NX_PER_AREA: 1/cm^2
• NX_FREQUENCY: 1/s
• NX_DIMENSIONLESS

This is what currently exists:

NXbeam
  flux[i]: (optional) NX_FLOAT {units=NX_FLUX}

NXmx
ENTRY: (required) NXentry
  BEAM: (required) NXbeam
   flux: (optional) NX_FLOAT {units=NX_FLUX}
   total_flux: (required) NX_FLOAT {units=NX_FREQUENCY}

This is the proposed changes in this MR (without the NXmonitor part, only the flux related things):

NXbeam
  flux[i]: (optional) NX_FLOAT {units=NX_FLUX}

NXmx
ENTRY: (required) NXentry
  BEAM: (required) NXbeam
   @flux: (optional) NX_CHAR
   total_flux: (optional) NX_FLOAT {units=NX_FREQUENCY}
   flux: (optional) NX_FLOAT {units=NX_FLUX}
   flux_integrated: (optional) NX_FLOAT {units=NX_PER_AREA}
   total_flux_integrated: (optional) NX_FLOAT {units=NX_DIMENSIONLESS}

So the word "integrated" stands for time integrated and the word "total" stands for area integrated.

The reason we cannot come up with sensible names like

• flux_integrated -> flux_time_integrated
• total_flux -> flux_area_integrated
• total_flux_integrated -> flux_time_and_area_integrated

is because NXmx already has total_flux.

Sorry @phyy-nx for my initial pessimistic view, the two units that were wrong scared the hell out of me. The names are very unfortunate but we already have total_flux in NXmx so I don't see another way either. I'd say we should not propagate these unfortunate names to NXbeam in the future.

I have no strong opinion on the addition of the optional NXmonitor.

[phyy-nx]

No worries, thanks for the comments. I'll review your comments more carefully as soon as I get a chance.

[yayahjb]

All existing MX ontologies have some unfortunate names, but it can be a disaster to make changes to existing tags used in large numbers of images, in this case, millions. The best you can do it to start a slow process of deprecation and recommendation of new names. Most of the tme it is not worth the effort. It could be worse. We could be back to when I was young and all of physics moved from default left-handed systems for E&M to right handed. I still have trouble with that, especially since I am a right-trained lefty.

…

On Tue, Mar 15, 2022 at 12:17 PM woutdenolf ***@***.***> wrote: Referenced units: - NX_FLUX: 1/s/cm^2 - NX_PER_AREA: 1/cm^2 - NX_FREQUENCY: 1/s - NX_DIMENSIONLESS This is what currently exists: NXbeam flux[i]: (optional) NX_FLOAT {units=NX_FLUX} NXmx ENTRY: (required) NXentry BEAM: (required) NXbeam flux: (optional) NX_FLOAT {units=NX_FLUX} total_flux: (required) NX_FLOAT {units=NX_FREQUENCY} This is the new proposal (without the NXmonitor part, only the *flux* related things): NXbeam flux[i]: (optional) NX_FLOAT {units=NX_FLUX} NXmx ENTRY: (required) NXentry BEAM: (required) NXbeam @Flux: (optional) NX_CHAR total_flux: (optional) NX_FLOAT {units=NX_FREQUENCY} flux: (optional) NX_FLOAT {units=NX_FLUX} flux_integrated: (optional) NX_FLOAT {units=NX_PER_AREA} total_flux_integrated: (optional) NX_FLOAT {units=NX_DIMENSIONLESS} So the word "integrated" stands for *time integrated* and the word "total" stands for *area integrated*. The reason we cannot come up with sensible names like - flux_integrated -> flux_time_integrated - total_flux -> flux_area_integrated - total_flux_integrated -> flux_time_and_area_integrated is because NXmx already has total_flux. Sorry @phyy-nx <https://github.com/phyy-nx> for my initial pessimistic view, the two units that were wrong scared the hell out of me. The names are very unfortunate but we already have total_flux in NXmx so I don't see another way either. I'd say we should not propagate these unfortunate names to NXbeam in the future. I have no strong opinion on the addition of the optional NXmonitor. — Reply to this email directly, view it on GitHub <#1035 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABB6EAKFIQRHI7ZFJ3YFTNDVACZXXANCNFSM5QXGUGGA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because your review was requested.Message ID: ***@***.***>

[woutdenolf]

I'll review your comments more carefully as soon as I get a chance.

@phyy-nx There is nothing to review, I didn't propose anything different. You can go ahead with what you have after fixing the units of flux_integrated and total_flux_integrated. I just described in my own words what my understanding is of your changes. If this corresponds with what you intended, then I have no further comments. After fixing those two units it is all clear now. The names are unfortunate but as I said, I don't think we can do better provided what is already in the standard.

but it can be a disaster to make changes to existing tags

For sure.

[woutdenolf]

@phyy-nx Maybe you could add a comment about flux integration to the respective fields?

• flux_integrated: flux integrated over time
• total_flux: flux integrated over area
• total_flux_integrated: flux integrated over time and area

You can understand that from the units but maybe it is good to mention it explicitly since the words "total" and "integrated" are not self explanatory.

[prjemian]

@phyy-nx Since this is labeled "NIAC should review", then is there anything to do at the Code Camp this month? If not, then remove this PR from the Code Camp project.

[woutdenolf]

I proposed a fix for all my comments in Merge #1082. You can merge it in this branch if you approve.

[phyy-nx]

Ok, I think that's all the feedback from the spring NIAC. I think we can remove the code camp label and vote on it this fall.

[woutdenolf]

LGTM

[prjemian]

GitHub reports a merge conflict with NXmx.nxdl.xml.

Also, since we will not merge this until the NIAC looks at it, can we convert this PR to draft state to prevent someone merging?

[phyy-nx]

Conflicts are fixed

[phyy-nx]

Conversation from code camp summer 2022. Since this needs a NIAC vote anyway, let's make as a goal to use the logic proposed in #1002 to enforce a choice between flux, total_flux, flux_integrated, total_flux_integrated, and the path to an NXmonitor with per-shot flux information. We'd like to have that ready by the fall NIAC meeting. Owners: @benajamin for finishing the new NXDL rule needed to enforce choices between fields and groups, and @phyy-nx to add the logic to this PR.

[phyy-nx]

From Fall 2022 NIAC, don't need to wait on #1002. Instead, vote on this, merge it, and add a new issue to require one of flux, total_flux, flux_integrated, total_flux_integrated

[prjemian]

There is a conflict involving the NXmonitor group.

[phyy-nx]

Conflicts fixed, ready for NIAC vote

[prjemian]

CI testing failed:

Warning, treated as error:
/home/runner/work/definitions/definitions/build/manual/source/classes/applications/NXmx.rst:1005:undefined label: 'nxmx-entry-instrument-beam-total-flux-field'
make: *** [Makefile:62: html] Error 2
Error: Process completed with exit code 2.

And that means my previous change was not correct. My apology. Please switch back to:

:ref:`flux </NXmx/ENTRY/INSTRUMENT/BEAM/flux-field>`

[prjemian]

LGTM

[benajamin]

The proposal is to accept the changes to NXmx represented by pull request #1035

[phyy-nx]

Thanks folks