설명

Returns a geometry with the same X/Y coordinates as the input geometry, and values from the raster copied into the M 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.

2.2.0 버전부터 사용할 수 있습니다.

예시

--
-- 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)

참고

ST_Value, ST_SetSRID