"""
Trellis Stacked Bar Chart
=========================
This is an example of a horizontal stacked bar chart using data which contains crop yields over different regions and different years in the 1930s.
"""
# category: bar charts
import altair as alt
from vega_datasets import data

source = data.barley()

alt.Chart(source).mark_bar().encode(
    column='year',
    x='yield',
    y='variety',
    color='site'
).properties(width=220)