PostGIS
Name
ST_SetM — 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_SetM*(`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_SetM(
rast,
band => 1,
geom => 'SRID=4326;LINESTRING(1.0 1.9, 1.0 0.2)'::geometry,
resample => 'bilinear'
))
FROM test_raster
st_astext
----------------------------------
LINESTRING M (1 1.9 38,1 0.2 27)