:orphan:
:html_theme.sidebar_secondary.remove:
.. This document is auto-generated by the altair-gallery extension. Do not modify directly.
.. _gallery_wheat_wages:
Wheat and Wages
---------------
A recreation of William Playfair's classic chart visualizing
the price of wheat, the wages of a mechanic, and the reigning British monarch.
This is a more polished version of the simpler chart in :ref:`gallery_bar_and_line_with_dual_axis`.
.. altair-plot::
:remove-code:
import altair as alt
import pandas as pd
from vega_datasets import data
base_wheat = alt.Chart(data.wheat.url).transform_calculate(year_end="+datum.year + 5")
base_monarchs = alt.Chart(data.monarchs.url).transform_calculate(
offset="((!datum.commonwealth && datum.index % 2) ? -1: 1) * 2 + 95",
off2="((!datum.commonwealth && datum.index % 2) ? -1: 1) + 95",
y="95",
x="+datum.start + (+datum.end - +datum.start)/2",
)
bars = base_wheat.mark_bar(fill="#aaa", stroke="#999").encode(
x=alt.X("year:Q", bin="binned", axis=alt.Axis(format="d", tickCount=5)).scale(
zero=False
),
y=alt.Y("wheat:Q", axis=alt.Axis(zindex=1)),
x2=alt.X2("year_end"),
)
section_data = pd.DataFrame(
[
{"year": 1600},
{"year": 1650},
{"year": 1700},
{"year": 1750},
{"year": 1800},
]
)
section_line = (
alt.Chart(section_data)
.mark_rule(stroke="#000", strokeWidth=0.6, opacity=0.7)
.encode(x=alt.X("year"))
)
area = base_wheat.mark_area(color="#a4cedb", opacity=0.7).encode(
x=alt.X("year:Q"), y=alt.Y("wages:Q")
)
area_line_1 = area.mark_line(color="#000", opacity=0.7)
area_line_2 = area.mark_line(yOffset=-2, color="#EE8182")
top_bars = base_monarchs.mark_bar(stroke="#000").encode(
x=alt.X("start:Q"),
x2=alt.X2("end"),
y=alt.Y("y:Q"),
y2=alt.Y2("offset"),
fill=alt.Fill(
"commonwealth:N", legend=None, scale=alt.Scale(range=["black", "white"])
),
)
top_text = base_monarchs.mark_text(yOffset=14, fontSize=9, fontStyle="italic").encode(
x=alt.X("x:Q"), y=alt.Y("off2:Q"), text=alt.Text("name:N")
)
(
(bars + section_line + area + area_line_1 + area_line_2 + top_bars + top_text)
.properties(width=900, height=400)
.configure_axis(title=None, gridColor="white", gridOpacity=0.25, domain=False)
.configure_view(stroke="transparent")
)
.. tab-set::
.. tab-item:: Method syntax
:sync: method
.. code:: python
import altair as alt
import pandas as pd
from vega_datasets import data
base_wheat = alt.Chart(data.wheat.url).transform_calculate(year_end="+datum.year + 5")
base_monarchs = alt.Chart(data.monarchs.url).transform_calculate(
offset="((!datum.commonwealth && datum.index % 2) ? -1: 1) * 2 + 95",
off2="((!datum.commonwealth && datum.index % 2) ? -1: 1) + 95",
y="95",
x="+datum.start + (+datum.end - +datum.start)/2",
)
bars = base_wheat.mark_bar(fill="#aaa", stroke="#999").encode(
alt.X("year:Q").bin("binned").axis(format="d", tickCount=5).scale(zero=False),
alt.Y("wheat:Q").axis(zindex=1),
alt.X2("year_end"),
)
section_data = pd.DataFrame(
[
{"year": 1600},
{"year": 1650},
{"year": 1700},
{"year": 1750},
{"year": 1800},
]
)
section_line = (
alt.Chart(section_data)
.mark_rule(stroke="#000", strokeWidth=0.6, opacity=0.7)
.encode(alt.X("year"))
)
area = base_wheat.mark_area(color="#a4cedb", opacity=0.7).encode(
alt.X("year:Q"), alt.Y("wages:Q")
)
area_line_1 = area.mark_line(color="#000", opacity=0.7)
area_line_2 = area.mark_line(yOffset=-2, color="#EE8182")
top_bars = base_monarchs.mark_bar(stroke="#000").encode(
alt.X("start:Q"),
alt.X2("end"),
alt.Y("y:Q"),
alt.Y2("offset"),
alt.Fill("commonwealth:N").legend(None).scale(range=["black", "white"]),
)
top_text = base_monarchs.mark_text(yOffset=14, fontSize=9, fontStyle="italic").encode(
alt.X("x:Q"), alt.Y("off2:Q"), alt.Text("name:N")
)
(
(bars + section_line + area + area_line_1 + area_line_2 + top_bars + top_text)
.properties(width=900, height=400)
.configure_axis(title=None, gridColor="white", gridOpacity=0.25, domain=False)
.configure_view(stroke="transparent")
)
.. tab-item:: Attribute syntax
:sync: attribute
.. code:: python
import altair as alt
import pandas as pd
from vega_datasets import data
base_wheat = alt.Chart(data.wheat.url).transform_calculate(year_end="+datum.year + 5")
base_monarchs = alt.Chart(data.monarchs.url).transform_calculate(
offset="((!datum.commonwealth && datum.index % 2) ? -1: 1) * 2 + 95",
off2="((!datum.commonwealth && datum.index % 2) ? -1: 1) + 95",
y="95",
x="+datum.start + (+datum.end - +datum.start)/2",
)
bars = base_wheat.mark_bar(fill="#aaa", stroke="#999").encode(
x=alt.X("year:Q", bin="binned", axis=alt.Axis(format="d", tickCount=5)).scale(
zero=False
),
y=alt.Y("wheat:Q", axis=alt.Axis(zindex=1)),
x2=alt.X2("year_end"),
)
section_data = pd.DataFrame(
[
{"year": 1600},
{"year": 1650},
{"year": 1700},
{"year": 1750},
{"year": 1800},
]
)
section_line = (
alt.Chart(section_data)
.mark_rule(stroke="#000", strokeWidth=0.6, opacity=0.7)
.encode(x=alt.X("year"))
)
area = base_wheat.mark_area(color="#a4cedb", opacity=0.7).encode(
x=alt.X("year:Q"), y=alt.Y("wages:Q")
)
area_line_1 = area.mark_line(color="#000", opacity=0.7)
area_line_2 = area.mark_line(yOffset=-2, color="#EE8182")
top_bars = base_monarchs.mark_bar(stroke="#000").encode(
x=alt.X("start:Q"),
x2=alt.X2("end"),
y=alt.Y("y:Q"),
y2=alt.Y2("offset"),
fill=alt.Fill(
"commonwealth:N", legend=None, scale=alt.Scale(range=["black", "white"])
),
)
top_text = base_monarchs.mark_text(yOffset=14, fontSize=9, fontStyle="italic").encode(
x=alt.X("x:Q"), y=alt.Y("off2:Q"), text=alt.Text("name:N")
)
(
(bars + section_line + area + area_line_1 + area_line_2 + top_bars + top_text)
.properties(width=900, height=400)
.configure_axis(title=None, gridColor="white", gridOpacity=0.25, domain=False)
.configure_view(stroke="transparent")
)