ecephys raster_plot plots each unit twice #1739
Description
Hi!
When running raster_plot (imported from allensdk.brain_observatory.ecephys.visualization) on a spike_times dataframe, the spike times from each unit is plotted twice (twice as many lines as it's supposed to).
This is because the function passed to pandas's aggregate (here, the call on the _VlPlotter object) is called on each column, thus once on the 'stimulus_presentation_id' and once on the 'time_since_stimulus_presentation_onset' column.
This can be fixed by passing only one column to the aggregate function, eg spike_times[['stimulus_presentation_id', 'unit_id']].groupby('unit_id').agg(plotter).
I'll follow up with a pull request in a moment!
Best
Daniel