:orphan:
:html_theme.sidebar_secondary.remove:

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

.. _gallery_wind_vector_map:


Wind Vector Map
---------------
An example showing a vector array map showing wind speed and direction using ``wedge``
as shape for ``mark_point`` and ``angle`` encoding for the wind direction.
This is adapted from this corresponding Vega-Lite Example:
`Wind Vector Map <https://vega.github.io/vega-lite/examples/point_angle_windvector.html>`_
with an added base map.


.. altair-plot::
    :remove-code:
    


    import altair as alt
    from vega_datasets import data

    df_wind = data.windvectors()
    data_world = alt.topo_feature(data.world_110m.url, "countries")

    wedge = (
        alt.Chart(df_wind)
        .mark_point(shape="wedge", filled=True)
        .encode(
            latitude="latitude",
            longitude="longitude",
            color=alt.Color(
                "dir", scale=alt.Scale(domain=[0, 360], scheme="rainbow"), legend=None
            ),
            angle=alt.Angle("dir", scale=alt.Scale(domain=[0, 360], range=[180, 540])),
            size=alt.Size("speed", scale=alt.Scale(rangeMax=500)),
        )
        .project("equalEarth")
    )

    xmin, xmax, ymin, ymax = (
        df_wind.longitude.min(),
        df_wind.longitude.max(),
        df_wind.latitude.min(),
        df_wind.latitude.max(),
    )

    # extent as feature or featurecollection
    extent = {
        "type": "Feature", 
        "geometry": {"type": "Polygon", 
                     "coordinates": [[
                         [xmax, ymax],
                         [xmax, ymin],
                         [xmin, ymin],
                         [xmin, ymax],
                         [xmax, ymax]]]
                    },
        "properties": {}
    }

    # use fit combined with clip=True
    base = (
        alt.Chart(data_world)
        .mark_geoshape(clip=True, fill="lightgray", stroke="black", strokeWidth=0.5)
        .project(type="equalEarth", fit=extent)
    )

    base + wedge

.. tab-set::

    .. tab-item:: Method syntax
        :sync: method

        .. code:: python


            import altair as alt
            from vega_datasets import data

            df_wind = data.windvectors()
            data_world = alt.topo_feature(data.world_110m.url, "countries")

            wedge = alt.Chart(df_wind).mark_point(shape="wedge", filled=True).encode(
                alt.Latitude("latitude"),
                alt.Longitude("longitude"),
                alt.Color("dir")
                    .scale(domain=[0, 360], scheme="rainbow")
                    .legend(None),
                alt.Angle("dir").scale(domain=[0, 360], range=[180, 540]),
                alt.Size("speed").scale(rangeMax=500)
            ).project("equalEarth")

            xmin, xmax, ymin, ymax = (
                df_wind.longitude.min(),
                df_wind.longitude.max(),
                df_wind.latitude.min(),
                df_wind.latitude.max(),
            )

            # extent as feature or featurecollection
            extent = {
                "type": "Feature", 
                "geometry": {"type": "Polygon", 
                             "coordinates": [[
                                 [xmax, ymax],
                                 [xmax, ymin],
                                 [xmin, ymin],
                                 [xmin, ymax],
                                 [xmax, ymax]]]
                            },
                "properties": {}
            }

            # use fit combined with clip=True
            base = (
                alt.Chart(data_world)
                .mark_geoshape(clip=True, fill="lightgray", stroke="black", strokeWidth=0.5)
                .project(type="equalEarth", fit=extent)
            )

            base + wedge


    .. tab-item:: Attribute syntax
        :sync: attribute

        .. code:: python


            import altair as alt
            from vega_datasets import data

            df_wind = data.windvectors()
            data_world = alt.topo_feature(data.world_110m.url, "countries")

            wedge = (
                alt.Chart(df_wind)
                .mark_point(shape="wedge", filled=True)
                .encode(
                    latitude="latitude",
                    longitude="longitude",
                    color=alt.Color(
                        "dir", scale=alt.Scale(domain=[0, 360], scheme="rainbow"), legend=None
                    ),
                    angle=alt.Angle("dir", scale=alt.Scale(domain=[0, 360], range=[180, 540])),
                    size=alt.Size("speed", scale=alt.Scale(rangeMax=500)),
                )
                .project("equalEarth")
            )

            xmin, xmax, ymin, ymax = (
                df_wind.longitude.min(),
                df_wind.longitude.max(),
                df_wind.latitude.min(),
                df_wind.latitude.max(),
            )

            # extent as feature or featurecollection
            extent = {
                "type": "Feature", 
                "geometry": {"type": "Polygon", 
                             "coordinates": [[
                                 [xmax, ymax],
                                 [xmax, ymin],
                                 [xmin, ymin],
                                 [xmin, ymax],
                                 [xmax, ymax]]]
                            },
                "properties": {}
            }

            # use fit combined with clip=True
            base = (
                alt.Chart(data_world)
                .mark_geoshape(clip=True, fill="lightgray", stroke="black", strokeWidth=0.5)
                .project(type="equalEarth", fit=extent)
            )

            base + wedge