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

.. _gallery_layered_bar_chart:


Layered Bar Chart
-----------------
This example shows a bar chart showing the US population distribution of age groups and gender in 2000.


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

    
    import altair as alt
    from altair.expr import datum, if_
    from vega_datasets import data

    source = data.population.url

    alt.Chart(source).mark_bar(opacity=0.7).encode(
        alt.X('age:O', scale=alt.Scale(rangeStep=17)),
        alt.Y('sum(people):Q', axis=alt.Axis(title='population'), stack=None),
        alt.Color('gender:N', scale=alt.Scale(range=["#EA98D2", "#659CCA"]))
    ).transform_filter(
        datum.year == 2000
    ).transform_calculate(
        "gender", if_(datum.sex == 2, 'Female', 'Male')
    )


.. toctree::
   :hidden: