"""
Trellis Area Chart
------------------
This example shows small multiples of an area chart.
"""
# category: area charts
import altair as alt
from vega_datasets import data

source = data.iowa_electricity()

(
    alt.Chart(source)
    .mark_area()
    .encode(x="year:T", y="net_generation:Q", color="source:N", row="source:N")
    .properties(height=100)
)
