Is an extension necessary to create a column in the trials table that links to a specific TimeSeries?

[rly]

From @h-mayorquin on Slack:

Is an extension necessary to create a column in the trials table that links to a specific TimeSeries. Specifically, I want to create a link to a RoiResponseSeries?

[rly]

No, an extension is not necessary.

from pynwb import NWBFile, NWBHDF5IO, TimeSeries
from datetime import datetime, timezone
import numpy as np

nwbfile = NWBFile(
    session_description='session_description',
    identifier='identifier',
    session_start_time=datetime.now(timezone.utc),
)

time_series = TimeSeries(
    name='time_series',
    data=np.random.rand(100),
    timestamps=np.arange(100) * 0.1,
    unit='meters'
)

nwbfile.add_acquisition(time_series)

nwbfile.add_trial_column(name='column1', description='A column of object references')

nwbfile.add_trial(start_time=0.0, stop_time=1.0, column1=time_series)

with NWBHDF5IO('test.nwb', 'w') as io:
    io.write(nwbfile)

with NWBHDF5IO('test.nwb', 'r') as io:
    nwbfile = io.read()
    print(nwbfile.trials['column1'][0])  # Access the reference
    print(nwbfile.acquisition['time_series'])  # The same object