.. This document is auto-generated by the altair-gallery extension. Do not modify directly.

.. _gallery_mean_overlay_over_precipitiation_chart:


Layered Bar Chart with Line as Mean
-----------------------------------
This example shows mean overlay over precipitation chart.


.. altair-plot::
    :code-below:

    
    import altair as alt
    from vega_datasets import data

    source = data.seattle_weather()

    bar = alt.Chart(source).mark_bar().encode(
        x='month(date):O',
        y='mean(precipitation):Q'
    )

    rule = alt.Chart(source).mark_rule(color='red').encode(
        y='mean(precipitation)',
        size=alt.value(3)
    )

    bar + rule


.. toctree::
   :hidden: