.. This document is auto-generated by the altair-gallery extension. Do not modify directly.

.. _gallery_one_dot_per_zipcode:


One Dot Per Zipcode
-----------------------
This example shows a geographical plot with one dot per zipcode.


.. altair-plot::
    :code-below:

    
    import altair as alt
    from altair.expr import datum, substring
    from vega_datasets import data

    zipcodes = data.zipcodes.url

    alt.Chart(zipcodes).mark_circle(size=3).encode(
        longitude='longitude:Q',
        latitude='latitude:Q',
        color='digit:N'
    ).project(
        type='albersUsa'
    ).properties(
        width=650,
        height=400
    ).transform_calculate(
        "digit", substring(datum.zip_code, 0, 1)
    )


.. toctree::
   :hidden: