ST_Mean4ma — Raster processing function that calculates the mean pixel value in a neighborhood.
float8 ST_Mean4ma(
float8[][] matrix, text nodatamode, text[] VARIADIC args)
;
double precision ST_Mean4ma(
double precision[][][] value, integer[][] pos, text[] VARIADIC userargs)
;
Calculate the mean pixel value 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_mean4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+------------------ 2 | 253.222229003906 (1 row)
SELECT rid, st_value( ST_MapAlgebra(rast, 1, 'st_mean4ma(double precision[][][], integer[][], text[])'::regprocedure,'32BF', 'FIRST', NULL, 1, 1) , 2, 2) FROM dummy_rast WHERE rid = 2; rid | st_value -----+------------------ 2 | 253.222229003906 (1 row)