ST_Sum4ma
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## Name

ST_Sum4ma — Raster processing function that calculates the sum of all pixel values in a neighborhood.

## Synopsis

`float8 ST_Sum4ma(`float8[][] matrix, text nodatamode, text[] VARIADIC args`)`;

`double precision ST_Sum4ma(`double precision[][][] value, integer[][] pos, text[] VARIADIC userargs`)`;

## Description

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

## Examples

    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)

## See Also

ST_MapAlgebraFctNgb, ST_MapAlgebra (callback function version), ST_Min4ma, ST_Max4ma, ST_Mean4ma, ST_Range4ma, ST_Distinct4ma, ST_StdDev4ma

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