""" Interactive Rectangular Brush ============================= This example shows how to add a simple rectangular brush to a scatter plot. By clicking and dragging on the plot, you can highlight points within the range. """ # category: interactive charts import altair as alt from vega_datasets import data source = data.cars() brush = alt.selection(type='interval') alt.Chart(source).mark_point().encode( x='Horsepower:Q', y='Miles_per_Gallon:Q', color=alt.condition(brush, 'Cylinders:O', alt.value('grey')), ).add_selection(brush)