ST_SummaryStatsAgg

Name

ST_SummaryStatsAgg — Aggregate. Returns summarystats consisting of count, sum, mean, stddev, min, max for a given raster band of a set of raster. Band 1 is assumed is no band is specified.

Synopsis

summarystats ST_SummaryStatsAgg ( raster rast , integer nband , boolean exclude_nodata_value , double precision sample_percent ) ;

summarystats ST_SummaryStatsAgg ( raster rast , boolean exclude_nodata_value , double precision sample_percent ) ;

summarystats ST_SummaryStatsAgg ( raster rast , integer nband , boolean exclude_nodata_value ) ;

Description

Returns summarystats consisting of count, sum, mean, stddev, min, max for a given raster band of a raster or raster coverage. If no band is specified nband defaults to 1.

[Note]

By default only considers pixel values not equal to the NODATA value. Set exclude_nodata_value to False to get count of all pixels.

[Note]

By default will sample all pixels. To get faster response, set sample_percent to value between 0 and 1

Availability: 2.2.0

Examples

WITH foo AS (
	SELECT
		rast.rast
	FROM (
		SELECT ST_SetValue(
			ST_SetValue(
				ST_SetValue(
					ST_AddBand(
						ST_MakeEmptyRaster(10, 10, 10, 10, 2, 2, 0, 0,0)
						, 1, '64BF', 0, 0
					)
					, 1, 1, 1, -10
				)
				, 1, 5, 4, 0
			)
			, 1, 5, 5, 3.14159
		) AS rast
	) AS rast
	FULL JOIN (
		SELECT generate_series(1, 10) AS id
	) AS id
		ON 1 = 1
)
SELECT
	(stats).count,
	round((stats).sum::numeric, 3),
	round((stats).mean::numeric, 3),
	round((stats).stddev::numeric, 3),
	round((stats).min::numeric, 3),
	round((stats).max::numeric, 3)
FROM (
	SELECT
		ST_SummaryStatsAgg(rast, 1, TRUE, 1) AS stats
	FROM foo
) bar;

 count |  round  | round  | round |  round  | round
-------+---------+--------+-------+---------+-------
    20 | -68.584 | -3.429 | 6.571 | -10.000 | 3.142
(1 row)