python - multi_line hover in bokeh

Question

As in this question:

I found that hovertool is not implemented for multi_line plots which is a bit of a setback. This is mentioned under 'warnings' here: http://docs.bokeh.org/en/0.11.0/docs/reference/models/tools.html#bokeh.models.tools.HoverTool

Is there any work arounds for this? Also, If I were to implement this feature, what would be a good place to start and is there anything specific to be aware of? Also, is this feature in the current Bokeh roadmap?

As it happens this will probably be looked at by someone at Continuum this week, in response to a need on a client project, so you may be in luck soon. — bigreddot
@bigreddot do you know if this is still happening? Highlighting lines in Bokeh would be a really cool feature. — jonalm

bigreddot bigreddot · Accepted Answer · 2017-03-10T00:06:41

As of Bokeh 0.12.4 (earlier, actually but I forget the exact release) the hover tool supports mutli_line:

from collections import defaultdict

import numpy as np
from scipy.stats import norm

from bokeh.plotting import show, figure
from bokeh.models import ColumnDataSource, HoverTool
from bokeh.palettes import Viridis6

RT_x = np.linspace(118, 123, num=50)

mass_spec = defaultdict(list)
for scale, mz in [(1.0, 83), (0.9, 55), (0.6, 98), (0.4, 43), (0.2, 39), (0.12, 29)]:
    mass_spec["RT"].append(RT_x)
    mass_spec["RT_intensity"].append(norm(loc=120.4).pdf(RT_x) * scale)
    mass_spec['MZ_tip'].append(mz)
    mass_spec['Intensity_tip'].append(scale)
mass_spec['color'] = Viridis6

source = ColumnDataSource(mass_spec)

p = figure(plot_height=400)
p.multi_line(xs='RT', ys='RT_intensity', legend="Intensity_tip",
             line_width=5, line_color='color', line_alpha=0.6,
             hover_line_color='color', hover_line_alpha=1.0,
             source=source)

p.add_tools(HoverTool(show_arrow=False, line_policy='next', tooltips=[
    ('MZ', '@MZ_tip'),
    ('Rel Intensity', '@Intensity_tip')
]))

show(p)

Which results in

python - multi_line hover in bokeh

1 Answers