customjs_for_hover#
An interactive plot showcasing Bokeh’s ability to add interactions using Custom Javascript.
This example demonstrates adding links between points on a graph.
These lines only show on hover using CustomJS
callbacks to update the plot.
Details
- Bokeh APIs:
figure.add_tools
,bokeh.models.HoverTool
,bokeh.models.ColumnDataSource
,bokeh.models.CustomJS
- More info:
- Keywords:
hover, javascript callback, CustomJS
from bokeh.models import ColumnDataSource, CustomJS, HoverTool
from bokeh.plotting import figure, show
# define some points and a little graph between them
x = [2, 3, 5, 6, 8, 7]
y = [6, 4, 3, 8, 7, 5]
links = {
0: [1, 2],
1: [0, 3, 4],
2: [0, 5],
3: [1, 4],
4: [1, 3],
5: [2, 3, 4],
}
p = figure(width=400, height=400, tools="", toolbar_location=None, title='Hover over points')
source = ColumnDataSource({'x0': [], 'y0': [], 'x1': [], 'y1': []})
sr = p.segment(x0='x0', y0='y0', x1='x1', y1='y1', color='olive', alpha=0.6, line_width=3, source=source )
cr = p.circle(x, y, color='olive', size=30, alpha=0.4, hover_color='olive', hover_alpha=1.0)
# add a hover tool that sets the link data for a hovered circle
code = """
const links = %s
const data = {'x0': [], 'y0': [], 'x1': [], 'y1': []}
const indices = cb_data.index.indices
for (let i = 0; i < indices.length; i++) {
const start = indices[i]
for (let j = 0; j < links[start].length; j++) {
const end = links[start][j]
data['x0'].push(circle.data.x[start])
data['y0'].push(circle.data.y[start])
data['x1'].push(circle.data.x[end])
data['y1'].push(circle.data.y[end])
}
}
segment.data = data
""" % links
callback = CustomJS(args={'circle': cr.data_source, 'segment': sr.data_source}, code=code)
p.add_tools(HoverTool(tooltips=None, callback=callback, renderers=[cr]))
show(p)