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
