
:orphan:
:html_theme.sidebar_secondary.remove:

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

.. _gallery_bar_chart_with_mean_line:


Bar Chart with Line at Mean
---------------------------
This example shows the mean value overlaid on a bar chart.


.. altair-plot::
    :remove-code:
    


    import altair as alt
    from altair.datasets import data

    source = data.wheat()

    bar = alt.Chart(source).mark_bar().encode(
        x='year:O',
        y='wheat:Q'
    )

    rule = alt.Chart(source).mark_rule(color='red').encode(
        y='mean(wheat):Q'
    )

    (bar + rule).properties(width=600)
    # No channel encoding options are specified in this chart
    # so the code is the same as for the method-based syntax.


.. tab-set::

    .. tab-item:: Method syntax
        :sync: method

        .. code:: python


            import altair as alt
            from altair.datasets import data

            source = data.wheat()

            bar = alt.Chart(source).mark_bar().encode(
                x='year:O',
                y='wheat:Q'
            )

            rule = alt.Chart(source).mark_rule(color='red').encode(
                y='mean(wheat):Q'
            )

            (bar + rule).properties(width=600)


    .. tab-item:: Attribute syntax
        :sync: attribute

        .. code:: python


            import altair as alt
            from altair.datasets import data

            source = data.wheat()

            bar = alt.Chart(source).mark_bar().encode(
                x='year:O',
                y='wheat:Q'
            )

            rule = alt.Chart(source).mark_rule(color='red').encode(
                y='mean(wheat):Q'
            )

            (bar + rule).properties(width=600)
            # No channel encoding options are specified in this chart
            # so the code is the same as for the method-based syntax.
