.. 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::
    :code-below:

    
    import altair as alt
    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", axis=alt.Axis(format='d', tickCount=5)),
        y=alt.Y("wheat:Q", axis=alt.Axis(zindex=1)),
        x2=alt.X2("year_end")
    )

    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 + 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"
    )

.. toctree::
   :hidden: