Multi-panel Scatter Plot with Linked Brushing

This is an example of using an interval selection to control the color of points across multiple panels.

Method syntax

import altair as alt
from vega_datasets import data

source = data.cars()

brush = alt.selection_interval(resolve='global')

base = alt.Chart(source).mark_point().encode(
    y='Miles_per_Gallon',
    color=alt.condition(brush, 'Origin', alt.ColorValue('gray')),
).add_params(
    brush
).properties(
    width=250,
    height=250
)

base.encode(x='Horsepower') | base.encode(x='Acceleration')

Attribute syntax

import altair as alt
from vega_datasets import data

source = data.cars()

brush = alt.selection_interval(resolve='global')

base = alt.Chart(source).mark_point().encode(
    y='Miles_per_Gallon',
    color=alt.condition(brush, 'Origin', alt.ColorValue('gray')),
).add_params(
    brush
).properties(
    width=250,
    height=250
)

base.encode(x='Horsepower') | base.encode(x='Acceleration')
# No channel encoding options are specified in this chart
# so the code is the same as for the method-based syntax.