This topic describes the ST_SummaryStats function. This function is used to calculate the statistics of a specified set of bands that are contained in a raster object.
Syntax
raster ST_SummaryStats(raster raster_obj)
raster ST_SummaryStats(raster raster_obj, cstring statsOption)
raster ST_SummaryStats(raster raster_obj,
cstring bands,
cstring statsOption)Parameters
| Parameter | Description |
|---|---|
| raster_obj | The name of the raster object. |
| bands | The sequence numbers of the bands. The value of this parameter can be an array of
integers or an integer range. The integers start from 0. Examples: '0', '1-3', and '1,2,3'.
|
| statsOptions | The JSON string to specify the statistics that you want to calculate. |
The following table describes the parameter that is contained in the value of the statsOptions parameter.
| Parameter | Description | Type | Format | Default value | Remarks |
|---|---|---|---|---|---|
| approx | Specifies whether to use the sampling method to calculate statistics. | boolean | None | true |
|
Examples:
Calculate the statistics for a specified set of bands that are contained in a raster object.
UPDATE raster_obj SET raster_obj=ST_SummaryStats(raster_obj) WHERE id = 1;
UPDATE rast SET rast=ST_SummaryStats(rast,'0-2','{"approx":false}') WHERE id = 1;
UPDATE rast SET rast=ST_SummaryStats(rast,'{"approx":false}') WHERE id = 1;