float8_in float8_out hash_bytes_uint32 hash_bytes_uint32_extended int4_in int4_out int8_in int8_out INTERVAL_IS_NOBEGIN INTERVAL_IS_NOEND interval_negate INTERVAL_NOBEGIN INTERVAL_NOEND INTERVAL_NOT_FINITE pg_datan pg_datan2 pg_date_in pg_date_out pg_dcos pg_dsin pg_hashfloat8 pg_hashfloat8extended pg_hashint8 pg_hashint8extended pg_hashtext pg_hashtextextended pg_interval_cmp pg_interval_in pg_interval_justify_hours pg_interval_out pg_timestamp_in pg_timestamp_out pg_timestamptz_in pg_timestamptz_out

pg_datan() float8 pg_datan ( float8  arg1 ) Return the arctan of a double (radians) Note PostgreSQL function: datan(PG_FUNCTION_ARGS)