pylusat.zonal module

pylusat.zonal.zonal_stats_raster(zone_gdf, raster, stats=None, stats_prefix='zonal', nodata=None)

Calculate specified stats for each geometry in the zone GeoDataFrame.

If raster and zone GeoDataFrame were in different spatial reference systems, the raster will be warped (reprojected) to match the spatial reference of the zone GeoDataFrame.

Parameters:

  • zone_gdf (geopandas.GeoDataFrame) – The zone GeoDataFrame whose geometry must be polygon.

  • raster (str) – A path to a tif file or a connection string to a raster on PostgreSQL. The raster dataset whose values are summarized.

  • stats (list of str, or space-delimited str, optional) – Which statistics to calculate for each zone. Defaults to rasterstats.utils.DEFAULT_STATS, i.e., [‘count’, ‘min’, ‘max’, ‘mean’]. Other valid stats are [‘sum’, ‘std’, ‘median’, ‘majority’, ‘minority’, ‘unique’, ‘range’, ‘nodata’, ‘nan’]. See rasterstats for more details.

  • stats_prefix (str, default 'zonal') – The prefix used to name the output columns of the calculated stats. The output column name will be concatenated by a underscore. e.g., ‘zonal_mean’

  • nodata (int or float) – Value for no data cells.

Returns:

output_gdf – Returns a GeoDataFrame containing new column(s) for each type of statistic specified in the stats argument.

Return type:

geopandas.GeoDataFrame

Examples

Summarize values of habitat raster in each census tract zone.

>>> pylusat.zonal.zonal_stats_raster(acs2016_gdf, habitat_tif)
    GEOID10               ACRES TOTALPOP    zonal_max  zonal_mean  zonal_count
0   12001006001      267.844400     1371        42.0    32.425150         1303
1   12001006002      144.120683      710        42.0    32.484892          695
2   12001006003     1493.089927     2291        42.0    21.263203         6949
3   12001007001      128.644913      828        42.0    33.807512          639
4   12001007002     1026.058834     1465        42.0    25.799958         4804