Add BaseRasterWidget

[chrishalcrow]

Added BaseRasterWidget widget, and re-factored AmplitudeWidget, RasterWidget and DriftRasterMapWidget to use it.

Following on from @JoeZiminski's comment in #3649, I’ve made a BaseRasterWidget, which can be used to make spike times vs anything plots. Some advantages:

• Unifies the plotting logic for AmplitudeWidget, RasterWidget and DriftRasterMapWidget (and later LocationsWidget)
• Plotting kwargs from some widgets can now be used by others. E.g. y_lim and scatter_decimate from DriftRasterMapWidget is now available for AmplitudeWidget.

Now users (and devs!) can easily make custom raster plots, e.g. if you have a sorting analyzer called sa with spike_amplitudes computed, you can do:

all_spiketrains = {
    unit_id: sa.sorting.get_unit_spike_train(unit_id, segment_index=0, return_times=True) 
for unit_id in sa.sorting.unit_ids}

locations = sa.get_extension("spike_amplitudes").get_data(outputs="by_unit")[0]
x_locs_squares = {
    unit_id: pow(locations[unit_id],2)
for unit_id in sa.sorting.unit_ids}

BaseRasterWidget(spike_train_data=all_spiketrains, y_axis_data=x_locs_squares, unit_ids=[2,6], backend="matplotlib", y_lim=[0,50_000], title="Amplitudes Squared!!!", y_label="I love axis labels")

which makes this:

The goal was for this to be totally backend and not change any plots, but when doing it, I think it was a chance to unify some widget style choices. E.g. drawing just the left and bottom axes, and making the data fill the plot. It's a little difficult to test all this stuff. Here's a bunch of plots using main and this PR. I've also checking that SortingView can still do an amplitudes plot and played with ipywidgets a lot.

OLD vs NEW

[zm711]

I have to admit I like your style better with the edges removed. Looking classier to me. Something I've been meaning to suggest for a long time!

[zm711]

first round of comments. I think the main thing is actually making sure the segment handling is working as expected. I think a bug from before this refactor was being propagated.

[chrishalcrow]

There's currently different behaviour for plot_rasters and plot_amplitudes for a multi-segment analyzers.

• For plot_rasters, an error is raised if you forget to supply a segment_index (for a multi-segment recording).
• For plot_amplitudes, the 0th segment is chosen by default if no segment index is chosen.

Should we keep the different behaviours? Or unify the behaviour?

@samuelgarcia @zm711

[alejoe91]

There's currently different behaviour for plot_rasters and plot_amplitudes for a multi-segment analyzers.

• For plot_rasters, an error is raised if you forget to supply a segment_index (for a multi-segment recording).
• For plot_amplitudes, the 0th segment is chosen by default if no segment index is chosen.

Should we keep the different behaviours? Or unify the behaviour?

@samuelgarcia @zm711

Maybe warn and plot the first one?

[zm711]

I would say unify the behaviors in general. I only deal in mono segments so if Alessio is good with warn and do the first then that works for me for everything. I think I would lean toward error to force people to specify a segment so they realize this is only plotting one segment, but I'm also okay with a warning.

[zm711]

I'm sorry for this.