bigframes.bigquery.st_area

bigframes.bigquery.st_area(series: Series | GeoSeries) → Series

Returns the area in square meters covered by the polygons in the input GEOGRAPHY.

If geography_expression is a point or a line, returns zero. If geography_expression is a collection, returns the area of the polygons in the collection; if the collection doesn’t contain polygons, returns zero.

Note

BigQuery’s Geography functions, like st_area, interpret the geometry data type as a point set on the Earth’s surface. A point set is a set of points, lines, and polygons on the WGS84 reference spheroid, with geodesic edges. See: https://cloud.google.com/bigquery/docs/geospatial-data

Examples:

>>> import bigframes.geopandas
>>> import bigframes.pandas as bpd
>>> import bigframes.bigquery as bbq
>>> from shapely.geometry import Polygon, LineString, Point

>>> series = bigframes.geopandas.GeoSeries(
...         [
...             Polygon([(0.0, 0.0), (0.1, 0.1), (0.0, 0.1)]),
...             Polygon([(0.10, 0.4), (0.9, 0.5), (0.10, 0.5)]),
...             Polygon([(0.1, 0.1), (0.2, 0.1), (0.2, 0.2)]),
...             LineString([(0, 0), (1, 1), (0, 1)]),
...             Point(0, 1),
...         ]
... )
>>> series
0              POLYGON ((0 0, 0.1 0.1, 0 0.1, 0 0))
1    POLYGON ((0.1 0.4, 0.9 0.5, 0.1 0.5, 0.1 0.4))
2    POLYGON ((0.1 0.1, 0.2 0.1, 0.2 0.2, 0.1 0.1))
3                        LINESTRING (0 0, 1 1, 0 1)
4                                       POINT (0 1)
dtype: geometry

>>> bbq.st_area(series)
0    61821689.855985
1    494563347.88721
2    61821689.855841
3                0.0
4                0.0
dtype: Float64

Use round() to round the outputed areas to the neares ten millions

>>> bbq.st_area(series).round(-7)
0     60000000.0
1    490000000.0
2     60000000.0
3            0.0
4            0.0
dtype: Float64

Parameters:

series (bigframes.pandas.Series | bigframes.geopandas.GeoSeries) – A series containing geography objects.

Returns:

Series of float representing the areas.

Return type:

bigframes.pandas.Series