[Feature]: Add MeaningsTables to all DynamicTable rather than just EventsTable

[VisLab]

What would you like to see added to PyNWB?

1. Request that a timeline be given for merging ndx-events into core NWB. It is difficult to move forward with annotation and further development unless it is stably in the core.

2. Would like you to consider adding the MeaningsTable to any DynamicTable, maybe as an extended intermediate class X. Since any DynamicTable can in theory have CategoricalVectorData columns, it doesn't seem reasonable to restrict to just EventsTable, EventsTable would then extend X.

Thx @rly @bendichter @oruebel @yarikoptic

Is your feature request related to a problem?

Lack of stability is stymieing further development of annotation.

What solution would you like?

See above.

Do you have any interest in helping implement the feature?

Yes.

Code of Conduct

• I agree to follow this project's Code of Conduct
• Have you checked the Contributing document?
• Have you ensured this change was not already requested?

[bendichter]

DynamicTables are a generic data structure that is used to store many kinds of things, most of which are not event-related. For example, the electrodes used in electrophysiology, the ROIs of a calcium imaging experiment, and the fiber bundles in a fiber photometry experiment are all stored using DynamicTable.

There are a few sub-types of DynamicTable that are about temporal events:

• TimeIntervals - used for trials and epochs tables
• Events - in ndx-events, similar to a BIDS events file
• Units table - this store spike times and metadata for putative neurons in an ecephys experiment. I think these are technically events, but I don't see a clear use-case for HED.

I'd rather focus on TimeIntervals and Events rather than all DynamicTables and subtypes

[VisLab]

I understand your view, but I would have to disagree. MeaningTable objects are associated with CategoricalVectorData columns, which can appear in any DynamicTable. Even if you don't go for HED, the descriptions are useful. BTW HED is not restricted to time-related files. as illustrated by the Annotation Garden project. In any case, a first step is to get the mechanism into NWB :-).

[bendichter]

Yeah, we discussed this in the meeting today. I see now that the meanings table is useful beyond events. @rly is working on a solution in HDMF, which would propagate here