[MRG] Spikes raster plot colors

[gtdang]

Changed the spike raster colors to have a white background and use the current color cycle's first 4 colors.

Question:

• Should the API allow users to be able to specify colors?
  • With this new implementation the user could technically change the plot colors outside of the hnn-core API if they changed the Matplotlib color cycle and default background with the matplotlib API.

closes #888

[gtdang]

Hi @ntolley. I was looking into writing a test for making sure the colors are working expected for this plot. I was looking into the existing tests for the plotter in test_viz.py. It is shown below with the relevant tests for the plotter on lines 208-212. When I plot the spike event plot for the network specified I noticed that the plot was empty. Is this what we would expect for the network specified? The network only has 2 rhythmic drives added (lines 136-146).

hnn-core/hnn_core/tests/test_viz.py

Lines 124 to 240 in 9cdd05d

	def test_dipole_visualization(setup_net):
	"""Test dipole visualisations."""
	net = setup_net
	# Test plotting of simulations with no spiking
	dpls = simulate_dipole(net, tstop=100., n_trials=1)
	net.cell_response.plot_spikes_raster()
	net.cell_response.plot_spikes_hist()
	weights_ampa = {'L2_pyramidal': 5.4e-5, 'L5_pyramidal': 5.4e-5}
	syn_delays = {'L2_pyramidal': 0.1, 'L5_pyramidal': 1.}
	net.add_bursty_drive(
	'beta_prox', tstart=0., burst_rate=25, burst_std=5,
	numspikes=1, spike_isi=0, n_drive_cells=11, location='proximal',
	weights_ampa=weights_ampa, synaptic_delays=syn_delays,
	event_seed=14)
	net.add_bursty_drive(
	'beta_dist', tstart=0., burst_rate=25, burst_std=5,
	numspikes=1, spike_isi=0, n_drive_cells=11, location='distal',
	weights_ampa=weights_ampa, synaptic_delays=syn_delays,
	event_seed=14)
	dpls = simulate_dipole(net, tstop=100., n_trials=2, record_vsec='all')
	fig = dpls[0].plot() # plot the first dipole alone
	axes = fig.get_axes()[0]
	dpls[0].copy().smooth(window_len=10).plot(ax=axes) # add smoothed versions
	dpls[0].copy().savgol_filter(h_freq=30).plot(ax=axes) # on top
	# test decimation options
	plot_dipole(dpls[0], decim=2, show=False)
	for dec in [-1, [2, 2.]]:
	with pytest.raises(ValueError,
	match='each decimation factor must be a positive'):
	plot_dipole(dpls[0], decim=dec, show=False)
	# test plotting multiple dipoles as overlay
	fig = plot_dipole(dpls, show=False)
	# test plotting multiple dipoles with average
	fig = plot_dipole(dpls, average=True, show=False)
	plt.close('all')
	# test plotting dipoles with multiple layers
	fig, ax = plt.subplots()
	fig = plot_dipole(dpls, show=False, ax=[ax], layer=['L2'])
	fig = plot_dipole(dpls, show=False, layer=['L2', 'L5', 'agg'])
	fig, axes = plt.subplots(nrows=3, ncols=1)
	fig = plot_dipole(dpls, show=False, ax=axes, layer=['L2', 'L5', 'agg'])
	fig, axes = plt.subplots(nrows=3, ncols=1)
	fig = plot_dipole(dpls,
	show=False,
	ax=[axes[0], axes[1], axes[2]],
	layer=['L2', 'L5', 'agg'])
	plt.close('all')
	with pytest.raises(AssertionError,
	match="ax and layer should have the same size"):
	fig, axes = plt.subplots(nrows=3, ncols=1)
	fig = plot_dipole(dpls, show=False, ax=axes, layer=['L2', 'L5'])
	# multiple TFRs get averaged
	fig = plot_tfr_morlet(dpls, freqs=np.arange(23, 26, 1.), n_cycles=3,
	show=False)
	with pytest.raises(RuntimeError,
	match="All dipoles must be scaled equally!"):
	plot_dipole([dpls[0].copy().scale(10), dpls[1].copy().scale(20)])
	with pytest.raises(RuntimeError,
	match="All dipoles must be scaled equally!"):
	plot_psd([dpls[0].copy().scale(10), dpls[1].copy().scale(20)])
	with pytest.raises(RuntimeError,
	match="All dipoles must be sampled equally!"):
	dpl_sfreq = dpls[0].copy()
	dpl_sfreq.sfreq /= 10
	plot_psd([dpls[0], dpl_sfreq])
	# pytest deprecation warning for tmin and tmax
	with pytest.deprecated_call():
	plot_dipole(dpls[0], show=False, tmin=10, tmax=100)
	# test cell response plotting
	with pytest.raises(TypeError, match="trial_idx must be an instance of"):
	net.cell_response.plot_spikes_raster(trial_idx='blah', show=False)
	net.cell_response.plot_spikes_raster(trial_idx=0, show=False)
	fig = net.cell_response.plot_spikes_raster(trial_idx=[0, 1], show=False)
	assert len(fig.axes[0].collections) > 0, "No data plotted in raster plot"
	with pytest.raises(TypeError, match="trial_idx must be an instance of"):
	net.cell_response.plot_spikes_hist(trial_idx='blah')
	net.cell_response.plot_spikes_hist(trial_idx=0, show=False)
	net.cell_response.plot_spikes_hist(trial_idx=[0, 1], show=False)
	net.cell_response.plot_spikes_hist(color='r')
	net.cell_response.plot_spikes_hist(color=['C0', 'C1'])
	net.cell_response.plot_spikes_hist(color={'beta_prox': 'r',
	'beta_dist': 'g'})
	net.cell_response.plot_spikes_hist(
	spike_types={'group1': ['beta_prox', 'beta_dist']},
	color={'group1': 'r'})
	net.cell_response.plot_spikes_hist(
	spike_types={'group1': ['beta']}, color={'group1': 'r'})
	with pytest.raises(TypeError, match="color must be an instance of"):
	net.cell_response.plot_spikes_hist(color=123)
	with pytest.raises(ValueError):
	net.cell_response.plot_spikes_hist(color='z')
	with pytest.raises(ValueError):
	net.cell_response.plot_spikes_hist(color={'beta_prox': 'z',
	'beta_dist': 'g'})
	with pytest.raises(TypeError, match="Dictionary values of color must"):
	net.cell_response.plot_spikes_hist(color={'beta_prox': 123,
	'beta_dist': 'g'})
	with pytest.raises(ValueError, match="'beta_dist' must be"):
	net.cell_response.plot_spikes_hist(color={'beta_prox': 'r'})
	plt.close('all')

Here's a code snip to recreate:

from hnn_core import simulate_dipole, jones_2009_model, read_params
from pathlib import Path

hnn_core_root = Path.cwd().parents[0]
params_fname = Path(hnn_core_root, 'param', 'default.json')
params = read_params(params_fname)
net = jones_2009_model(params, mesh_shape=(3, 3))

weights_ampa = {'L2_pyramidal': 5.4e-5, 'L5_pyramidal': 5.4e-5}
syn_delays = {'L2_pyramidal': 0.1, 'L5_pyramidal': 1.}

net.add_bursty_drive(
    'beta_prox', tstart=0., burst_rate=25, burst_std=5,
    numspikes=1, spike_isi=0, n_drive_cells=11, location='proximal',
    weights_ampa=weights_ampa, synaptic_delays=syn_delays,
    event_seed=14)

net.add_bursty_drive(
    'beta_dist', tstart=0., burst_rate=25, burst_std=5,
    numspikes=1, spike_isi=0, n_drive_cells=11, location='distal',
    weights_ampa=weights_ampa, synaptic_delays=syn_delays,
    event_seed=14)

dpls = simulate_dipole(net, tstop=100., n_trials=2, record_vsec='all')

fig1 = net.cell_response.plot_spikes_raster()
fig1.show()

[ntolley]

@gtdang this test was written for the edge case with the drives are too weak to produce spiking activity in the network

There was an earlier bug where the plotting function would throw an error if not spikes occurred, so this test is to make sure that an empty plot is generated (the desired behavior in these simulations)

[ntolley]

If you want spiking just change the weights to a bigger number like 0.1 or 1.0!

[jasmainak]

bad idea to have a default list in a function. You will get funky effects in Python ... default should not be a mutable

[gtdang]

Thanks, we're going to refactor this call to be aligned with the plot_spikes_hist implementation so that it can also take a dict of color assignments. I don't think we need to expose the cell_types as an argument... though I wish there was a way to get it dynamically from the network instead of hard-coding the types.

[jasmainak]

see #916 ... it allows you to dynamically extract the cell types

[jasmainak]

missing docstring

[jasmainak]

I don't fully follow the categorization ... maybe docstrings will clarify

[jasmainak]

while you are at it, I am wondering if this could be addressed as well. The following line:

cell_type_ypos.append(-gid)

causes cells that spike with neighboring gids to overlap. I have been staring at these raster plots recently and it's very hard to tell how many times the same cell spiked (important to understand the underlying dynamics). Adding a small offset between nearby cells should address that problem

[gtdang]

I took a look into this. The overlap is due to both the y-position as you've identified and the line lengths defined during the plot function call on line 568. The y-position is the center of each line and the length is how much it extends from that center point (+-2.5 each way for a value of 5).

hnn-core/hnn_core/viz.py

Lines 559 to 568 in 27c6fc1

	for gid in cell_type_gids:
	gid_time = spike_times[spike_gids == gid]
	cell_type_times.append(gid_time)
	cell_type_ypos.append(-gid)
	if cell_type_times:
	events.append(
	ax.eventplot(cell_type_times, lineoffsets=cell_type_ypos,
	color=cell_type_colors[cell_type],
	label=cell_type, linelengths=5))

A simple solution is to change the line length to 1. However the lines will look more like dots with this change.

Another solution would be to analyze the cell times and gids, and apply a larger y-offset if they are within an X and Y bounding box of one another.

Let me know what you think.

[jasmainak]

I'm okay with the spikes looking like dots ... it's just a function of the number of cells in our network. Did a quick google image search of "spike raster plot" and the plots do look dotted when there are more neurons. I guess the y-offset = -gid is helpful since it allows you to identify the cell, so maybe best not to touch that. @ntolley any opinion here?