Schema
Owner
postgres
Descriptions
args: rast, band, pt, exclude_nodata_value=true - Returns the value of a given band in a given columnx, rowy pixel or at a particular geometric point. Band numbers start at 1 and assumed to be 1 if not specified. If exclude_nodata_value is set to false, then all pixels include nodata pixels are considered to intersect and return value. If exclude_nodata_value is not passed in then reads it from metadata of raster.
Options
Option | Value |
---|---|
Returns |
double precision |
Language |
|
Parameters |
rast public.raster band integer pt public.geometry exclude_nodata_value boolean = true |
Definition
CREATE OR REPLACE FUNCTION public.st_value (
rast public.raster,
band integer,
pt public.geometry,
exclude_nodata_value boolean = true
)
RETURNS double precision AS
$span$
DECLARE
x float8;
y float8;
gtype text;
BEGIN
gtype := public.ST_geometrytype(pt);
IF ( gtype != 'ST_Point' ) THEN
RAISE EXCEPTION 'Attempting to get the value of a pixel with a non-point geometry';
END IF;
IF public.ST_SRID(pt) != public.ST_SRID(rast) THEN
RAISE EXCEPTION 'Raster and geometry do not have the same SRID';
END IF;
x := public.ST_x(pt);
y := public.ST_y(pt);
RETURN public.ST_value(rast,
band,
public.ST_worldtorastercoordx(rast, x, y),
public.ST_worldtorastercoordy(rast, x, y),
exclude_nodata_value);
END;
$span$
LANGUAGE 'plpgsql'
IMMUTABLE
RETURNS NULL ON NULL INPUT
SECURITY INVOKER
COST 100;
COMMENT ON FUNCTION public.st_value(rast public.raster, band integer, pt public.geometry, exclude_nodata_value boolean)
IS 'args: rast, band, pt, exclude_nodata_value=true - Returns the value of a given band in a given columnx, rowy pixel or at a particular geometric point. Band numbers start at 1 and assumed to be 1 if not specified. If exclude_nodata_value is set to false, then all pixels include nodata pixels are considered to intersect and return value. If exclude_nodata_value is not passed in then reads it from metadata of raster.';
This file was generated with SQL Manager for PostgreSQL (www.pgsqlmanager.com) at 13/03/2014 13:23 |