how to construct trials table?

[bendichter]

We have it working that you can create a dynamictable in pynwb and read it in matnwb, but I do not know how to do the reverse. Can you give me a minimal example for constructing a trials or units table in matnwb?

[lawrence-mbf]

For trials:

columnNames = {'start'};
nwb.trials = types.core.DynamicTable(...
    'colnames', columnNames,...
    'description', 'trial data and properties', ...
    'id', types.core.ElementIdentifiers('data', 1:10));

for i=1:length(columnNames)
    nwb.trials.tablecolumn.set(columnNames{i}, ...
        types.core.TableColumn('data', <some vector>));
end

Things to note that may impact compatibility:

1. There are no checks for guaranteeing that the names in colnames match the entries in tablecolumn.
2. There are no checks guaranteeing rectangular shape of the DynamicTable (that all columns have the same number of elements as the id)

3. 43 so the the presence of a 'start' column is not checked for, either in name or as a tablecolumn entry.

I believe all three can actually be worked around by subclassing DynamicTable and writing the checks manually.

[bendichter]

perfect! Thanks for the speedy response!

[bendichter]

OK, what did I do wrong?

nwb = nwbfile;

nwb.trials = types.core.DynamicTable(...
    'colnames', {'start','stop','condition'},...
    'description', 'trial data and properties', ...
    'id', types.core.ElementIdentifiers('data', 1:3));

nwb.trials.tablecolumn.set('start', ...
    types.core.TableColumn('data', [.5, 1.5, 2.5]));

nwb.trials.tablecolumn.set('stop', ...
    types.core.TableColumn('data', [1., 2., 3.]));

nwb.trials.tablecolumn.set('condition', ...
    types.core.TableColumn('data', [0,1,0]));

nwbExport(nwb, 'test_trials.nwb')

[lawrence-mbf]

Is there an error message? It runs fine on my machine.

[bendichter]

hmm let me update... yup, that was it. Thanks!