Telco 20210728


Monday, 28th July, 13:00 UTC






In June, PC has promised to review the code for the NeXus ontology. He reports that comments have been provided, but that no further actions have happened yet.

The European HDF users group summer 2021 meeting was attended by a few NeXus representatives. BW commented that the talk on the HDF5 embedded user functions looks very powerful, but far too risky for widespread adoption. AB commented that it would solve his issues of online data normalisation that he is currently addressing via a custom reader in DIALS that has a hardcoded formula and knows where to find the relevant pedestal and gain values to apply.

Further discussion on adding NXcounts as a NeXus unit showed that nobody present objected to such an addition, but some wanted to make sure that there was full opportunity for anyone on the NIAC to raise an objection. It was not clear that the addition of NXcounts was significant enough to warrant a full NIAC vote (maybe the omission is just a bug that needs fixing, rather than a change to the stadard), so BW suggested starting by posting on the NIAC mailing list to request opinions.

Revisiting the question about scanning in NXfluo with the new info from the issue creator, it seems that NXstxm is a good fit. MK commented that NeXus has a general scanning strategy, but it isn’t formally written down. This would make a good project for a future code camp.

A new issue requests adding MetalJet as a new NXsource type. There is general agreement that new laboratory X-ray sources have been developed and are common enough to merit a new NXsource type. However, BW thinks that MetalJet might be too narrow and that “liquid jet” might be a more appropriate category name since there also exists X-ray sources based on jets of nitrogen or water. BW will ask for further opinions on the mailing list.

New NDXL images BW questions anySimpleType, PJ says it comes from XML.

AB brought up again the request to add a git revision attribute to NXentry. While it was generally agreed that people were free to add extra info to their files, there were some questions about the merits of any strategy that would require knowing the git revision rather than just the NeXus release version. AB was unsure (and would ask his collaboarators), but thought is was about being able to find the full NXDL specifications online. It was noted that the releases page for the github repository listed the commit ids together with the release versions and that this might be helpful.

Since many people expect to be busy in the end of August, the next telco will aim for early to mid september.