SELECT iterated_median_filter(v::double precision, 5) over() FROM generate_series(1, 10) as t(v);
 iterated_median_filter 
------------------------
                      1
                      2
                      3
                      4
                      5
                      6
                      7
                      8
                      8
                      8
(10 rows)

SELECT iterated_median_filter(v, 3) over() FROM (VALUES (1), (1.1), (0.9), (1.1), (0.95), (2.1), (1.95), (2.0), (2.05), (3.11), (2.99), (3.05), (3.0)) as t(v);
 iterated_median_filter 
------------------------
                      1
                      1
                      1
                    1.1
                    1.1
                   1.95
                      2
                      2
                   2.05
                   2.99
                      3
                      3
                      3
(13 rows)

SELECT iterated_median_filter(v, 3, 'inf'::double precision) over() FROM (VALUES (1), (1.1), (0.9), (1.1), (0.95), (2.1), (1.95), (2.0), (2.05), (3.11), (2.99), (3.05), (3.0)) as t(v);
 iterated_median_filter 
------------------------
                      1
                      1
                    1.1
                   0.95
                    1.1
                   1.95
                      2
                      2
                   2.05
                   2.99
                   3.05
                      3
                      3
(13 rows)