ST_SetZ
Name
ST_SetZ — Returns a geometry with the same X/Y coordinates as the input geometry, and values from the raster copied into the Z dimension using the requested resample algorithm.
Synopsis
geometry
ST_SetZ
(
raster
rast
, geometry
geom
, text
resample=nearest
, integer
band=1
)
;
Description
Returns a geometry with the same X/Y coordinates as the input geometry, and values from the raster copied into the Z dimensions using the requested resample algorithm.
The
resample
parameter can be set to "nearest" to copy the values from the cell each vertex falls within, or "bilinear" to use
bilinear interpolation
to calculate a value that takes neighboring cells into account also.
Availability: 3.2.0
Examples
--
-- 2x2 test raster with values
--
-- 10 50
-- 40 20
--
WITH test_raster AS (
SELECT
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(width => 2, height => 2,
upperleftx => 0, upperlefty => 2,
scalex => 1.0, scaley => -1.0,
skewx => 0, skewy => 0, srid => 4326),
index => 1, pixeltype => '16BSI',
initialvalue => 0,
nodataval => -999),
1,1,1,
newvalueset =>ARRAY[ARRAY[10.0::float8, 50.0::float8], ARRAY[40.0::float8, 20.0::float8]]) AS rast
)
SELECT
ST_AsText(
ST_SetZ(
rast,
band => 1,
geom => 'SRID=4326;LINESTRING(1.0 1.9, 1.0 0.2)'::geometry,
resample => 'bilinear'
))
FROM test_raster
st_astext
----------------------------------
LINESTRING Z (1 1.9 38,1 0.2 27)