: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.