given a PostGIS table `lname` with `lat` and `lon` columns and primay key `gid`, make a cluster filtering by `filtercol` column with `filterval` value and excluding `excludecol` column with `excludeval` value

postgis-cluster-lat-lon-with-filters.sql

CREATE OR REPLACE FUNCTION get_domains_n(lname varchar, lat varchar, lon varchar, gid varchar, radius numeric, filtercol varchar, filterval varchar, excludecol varchar, excludeval varchar)
    RETURNS SETOF record AS
$$
DECLARE
    lid_new    integer;
    dmn_number integer := 1;
    outr       record;
    innr       record;
    r          record;
BEGIN

    DROP TABLE IF EXISTS tmp;
    EXECUTE format('CREATE TEMPORARY TABLE tmp AS SELECT %I, ST_GeometryFromText('''||Concat('POINT(''||','%I','||'' ''||','%I','||'')')||''') AS geom FROM %I WHERE %I != %L AND %I = %L ', gid, lat, lon, lname, excludecol, excludeval, filtercol, filterval);
    ALTER TABLE tmp ADD COLUMN dmn integer;
    ALTER TABLE tmp ADD COLUMN chk boolean DEFAULT FALSE;
    EXECUTE 'UPDATE tmp SET dmn = '||dmn_number||', chk = FALSE WHERE '||gid||' = (SELECT MIN('||gid||') FROM tmp)';

    LOOP
        LOOP
            FOR outr IN EXECUTE 'SELECT '||gid||' AS gid, geom FROM tmp WHERE dmn = '||dmn_number||' AND NOT chk' LOOP
                FOR innr IN EXECUTE 'SELECT '||gid||' AS gid, geom FROM tmp WHERE dmn IS NULL' LOOP
                    IF ST_DWithin(ST_Transform(ST_SetSRID(outr.geom, 4326), 3785), ST_Transform(ST_SetSRID(innr.geom, 4326), 3785), radius) THEN
                        EXECUTE 'UPDATE tmp SET dmn = '||dmn_number||', chk = FALSE WHERE '||gid||' = '||innr.gid;
                    END IF;
                END LOOP;
                EXECUTE 'UPDATE tmp SET chk = TRUE WHERE '||gid||' = '||outr.gid;
            END LOOP;
            SELECT INTO r dmn FROM tmp WHERE dmn = dmn_number AND NOT chk LIMIT 1;
            EXIT WHEN NOT FOUND;
       END LOOP;
       SELECT INTO r dmn FROM tmp WHERE dmn IS NULL LIMIT 1;
       IF FOUND THEN
           dmn_number := dmn_number + 1;
           EXECUTE 'UPDATE tmp SET dmn = '||dmn_number||', chk = FALSE WHERE '||gid||' = (SELECT MIN('||gid||') FROM tmp WHERE dmn IS NULL LIMIT 1)';
       ELSE
           EXIT;
       END IF;
    END LOOP;

    RETURN QUERY EXECUTE 'SELECT ST_ConvexHull(ST_Collect(geom)) FROM tmp GROUP by dmn';

    RETURN;
END
$$
LANGUAGE plpgsql;

use it like so:

SELECT * FROM get_domains_n('mytable', 'latitude', 'longitude', 'id', 2, 'somecolumn', 'somevalue', 'someothercolumn', 'someothervalue') AS g(gm geometry);

code based on this StackOverflow answer but adapted for a table that has separate latitude and longitude columns (not the bestest of practices but this is what I have)

Just a heads up: If you add ".sql" on the end of your filename you'll get syntax highlighting. For some reason the SQL file type isn't doing it itself. (I noticed you were trying to use markdown to do it.)

done. thanks! was wondering why the heck it didn't go through...

updated the gist to use format in the main EXECUTE function so it is less vulnerable