ST_Sum4ma — Raster processing function that calculates the sum of all pixel values in a neighborhood.
float8 ST_Sum4ma(
float8[][] matrix, text nodatamode, text[] VARIADIC args)
;
double precision ST_Sum4ma(
double precision[][][] value, integer[][] pos, text[] VARIADIC userargs)
;
Calculate the sum of all pixel values in a neighborhood of pixels.
For Variant 2, a substitution value for NODATA pixels can be specified by passing that value to userargs.
Variant 1 is a specialized callback function for use as a callback parameter to ST_MapAlgebraFctNgb. |
Variant 2 is a specialized callback function for use as a callback parameter to ST_MapAlgebra (callback function version). |
Use of Variant 1 is discouraged since ST_MapAlgebraFctNgb has been deprecated as of 2.1.0. |
Availability: 2.0.0
Enhanced: 2.1.0 Addition of Variant 2
SELECT rid, st_value( st_mapalgebrafctngb(rast, 1, '32BF', 1, 1, 'st_sum4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+---------- 2 | 2279 (1 row)