: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 overlayed on a bar chart. .. altair-plot:: :remove-code: import altair as alt from vega_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 vega_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 vega_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.