:orphan: :html_theme.sidebar_secondary.remove: .. This document is auto-generated by the altair-gallery extension. Do not modify directly. .. _gallery_bar_chart_with_highlighted_segment: Bar Chart with Highlighted Segment ---------------------------------- This example shows a bar chart that highlights values beyond a threshold. .. altair-plot:: :remove-code: import altair as alt import pandas as pd from vega_datasets import data source = data.wheat() threshold = pd.DataFrame([{"threshold": 90}]) bars = alt.Chart(source).mark_bar().encode( x="year:O", y="wheat:Q", ) highlight = alt.Chart(source).mark_bar(color="#e45755").encode( x='year:O', y='baseline:Q', y2='wheat:Q' ).transform_filter( alt.datum.wheat > 90 ).transform_calculate("baseline", "90") rule = alt.Chart(threshold).mark_rule().encode( y='threshold:Q' ) (bars + highlight + 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 import pandas as pd from vega_datasets import data source = data.wheat() threshold = pd.DataFrame([{"threshold": 90}]) bars = alt.Chart(source).mark_bar().encode( x="year:O", y="wheat:Q", ) highlight = alt.Chart(source).mark_bar(color="#e45755").encode( x='year:O', y='baseline:Q', y2='wheat:Q' ).transform_filter( alt.datum.wheat > 90 ).transform_calculate("baseline", "90") rule = alt.Chart(threshold).mark_rule().encode( y='threshold:Q' ) (bars + highlight + rule).properties(width=600) .. tab-item:: Attribute syntax :sync: attribute .. code:: python import altair as alt import pandas as pd from vega_datasets import data source = data.wheat() threshold = pd.DataFrame([{"threshold": 90}]) bars = alt.Chart(source).mark_bar().encode( x="year:O", y="wheat:Q", ) highlight = alt.Chart(source).mark_bar(color="#e45755").encode( x='year:O', y='baseline:Q', y2='wheat:Q' ).transform_filter( alt.datum.wheat > 90 ).transform_calculate("baseline", "90") rule = alt.Chart(threshold).mark_rule().encode( y='threshold:Q' ) (bars + highlight + 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.