HoverTool for multiple data series in bokeh scatter plot

问题

I have the following small example script making use of numpy and bokeh:

import numpy as np
import bokeh.plotting as bp
from bokeh.objects import HoverTool 
bp.output_file('test.html')

fig = bp.figure(tools="reset,hover")
x = np.linspace(0,2*np.pi)
y1 = np.sin(x)
y2 = np.cos(x)
s1 = fig.scatter(x=x,y=y1,color='#0000ff',size=10,legend='sine')
s1.select(dict(type=HoverTool)).tooltips = {"x":"$x", "y":"$y"}
s2 = fig.scatter(x=x,y=y2,color='#ff0000',size=10,legend='cosine')
s2.select(dict(type=HoverTool)).tooltips = {"x":"$x", "y":"$y"}
bp.show()

The problem is that the hover tool only works for the cosine curve but not for the sine.

I know that one option would be to plot both series togehter and change the color of the cosine data points:

import numpy as np
import bokeh.plotting as bp
from bokeh.objects import HoverTool 
bp.output_file('test.html')

fig = bp.figure(tools="reset,hover")
x = np.linspace(0,2*np.pi)

y1 = np.sin(x)
y2 = np.cos(x)

x = np.array([x,x]).flatten()
y = np.array([y1,y2]).flatten()

blue = np.array('#0000ff').flatten()
red = np.array('#ff0000').flatten()
colors = np.array([blue.repeat(len(y1)),red.repeat(len(y1))]).flatten()

s1 = fig.scatter(x=x,y=y,color=colors,size=10,legend='sine & cosine')
s1.select(dict(type=HoverTool)).tooltips = {"x":"$x", "y":"$y"}
bp.show()

But then I loose the legend entry for the second color.

How do I manage to be able to hover over both data sets and see the corresponding tooltip?

Thanks!

Max

回答1:

This is actually a bug solved in master. I was fixed in this PR https://github.com/bokeh/bokeh/pull/1511

Also, you will need to modify your first code to use models instead of objects in the third line, as follow:

import numpy as np
import bokeh.plotting as bp
from bokeh.models import HoverTool 
bp.output_file('test.html')

fig = bp.figure(tools="reset,hover")
x = np.linspace(0,2*np.pi)
y1 = np.sin(x)
y2 = np.cos(x)
s1 = fig.scatter(x=x,y=y1,color='#0000ff',size=10,legend='sine')
s1.select(dict(type=HoverTool)).tooltips = {"x":"$x", "y":"$y"}
s2 = fig.scatter(x=x,y=y2,color='#ff0000',size=10,legend='cosine')
fig.select(dict(type=HoverTool)).tooltips = {"x":"$x", "y":"$y"}
bp.show()

Hope it helps!

Cheers.

Damian

UPDATED with comments below

回答2:

If you want to have multiple hover tools, you need to add multiple hover tools, each configured for a different renderer. You can add them this way:

p = figure()

r1 = p.circle([1,2,3], [4,5,6], color="blue")
p.add_tools(HoverTool(renderers=[r1], tooltips=TIPS))

r2 = p.square([4,5,6], [1,2,3], color="red")
p.add_tools(HoverTool(renderers=[r2], tooltips=TIPS))

来源：https://stackoverflow.com/questions/27545842/hovertool-for-multiple-data-series-in-bokeh-scatter-plot