Modify Units Table

[leesuyee]

I'm working with an existing ecephys NWB file (Zarr) and I'd like to make small modifications to the units table (change some column names and resort the column order) then write a new NWB file with the update. Is there a simple way to do this aside from re-constructing the units table row-by-row or column-by-column?

[oruebel]

I think there are two main options for this particular issue:

Option 1: Export One option would be to use export in PyNWB. In this case, I believe you would read the file as usual, then remove the columns you want to rename and re-add them with the new name. Alternatively, if that doesn't work, then I think you would indeed drop the whole units table and reconstruct it. The following tutorials on editing and exporting NWB files may be helpful for this:

• https://pynwb.readthedocs.io/en/stable/tutorials/advanced_io/plot_editing.html#sphx-glr-tutorials-advanced-io-plot-editing-py
• https://pynwb.readthedocs.io/en/stable/export.html
• https://hdmf.readthedocs.io/en/stable/export.html

Option 2: Manual Editing: If you only want to rename and re-order columns, then another option would be to do this directly via Zarr. I think in this case you would: 1) make a manual copy of the file, 2) use zarr.storage.rename() to rename the datasets of columns, 3) then update the colnames attribute of the units group to reflect the new names and order of columns, 4) use pynwb.validate or the nwbinspector to check that the file is indeed still valid. One gotcha to look out for is that if you have any indexed columns you will need to rename both the VectorData and the corresponding VectorIndex objects.

[leesuyee]

Thanks! I'll try this out.