Calculates the arctangent of number.
Syntax
double atan(<number>)Parameters
number: required. A value of the DOUBLE type. If the input value is of the STRING, BIGINT, or DECIMAL type, the value is implicitly converted into a value of the DOUBLE type before calculation.
Return value
A value of the DOUBLE type is returned. The value ranges from -π/2 to π/2. If the value of number is null, null is returned.
Sample data
This section provides sample source data and examples for you to understand how to use the functions. In this topic, a table named mf_math_fun_t is created and data is inserted into the table. Sample statements:
create table if not exists mf_math_fun_t(
int_data int,
bigint_data bigint,
double_data double,
decimal_data decimal,
float_data float,
string_data string
);
insert into mf_math_fun_t values
(null, -10, 0.525, 0.525BD, cast(0.525 as float), '10'),
(-20, null, -0.1, -0.1BD, cast(-0.1 as float), '-10'),
(0, -1, null, 20.45BD, cast(-1 as float), '30'),
(-40, 4, 0.89, null, cast(0.89 as float), '-30'),
(5, -50, -1, -1BD, null, '50'),
(-60, 6, 1.5, 1.5BD, cast(1.5 as float), '-50'),
(-1, -70, -7.5, -7.5BD, cast(-7.5 as float),null ),
(-80, 1, -10.2, -10.2BD, cast(-10.2 as float), '-1' ),
(9, -90, 2.58, 2.58BD, cast(2.58 as float), '0'),
(-100, 10, -5.8, -5.8BD, cast(-5.8 as float), '-90');Query data from the mf_math_fun_t table. Sample statement:
select * from mf_math_fun_t;
-- The following result is returned:
+------------+-------------+-------------+--------------+------------+-------------+
| int_data | bigint_data | double_data | decimal_data | float_data | string_data |
+------------+-------------+-------------+--------------+------------+-------------+
| NULL | -10 | 0.525 | 0.525 | 0.525 | 10 |
| -20 | NULL | -0.1 | -0.1 | -0.1 | -10 |
| 0 | -1 | NULL | 20.45 | -1.0 | 30 |
| -40 | 4 | 0.89 | NULL | 0.89 | -30 |
| 5 | -50 | -1.0 | -1 | NULL | 50 |
| -60 | 6 | 1.5 | 1.5 | 1.5 | -50 |
| -1 | -70 | -7.5 | -7.5 | -7.5 | NULL |
| -80 | 1 | -10.2 | -10.2 | -10.2 | -1 |
| 9 | -90 | 2.58 | 2.58 | 2.58 | 0 |
| -100 | 10 | -5.8 | -5.8 | -5.8 | -90 |
+------------+-------------+-------------+--------------+------------+-------------+Example: static data
-- The return value is 0.7853981633974483.
select atan(1);
-- The return value is -0.7853981633974483.
select atan(-1);
-- The return value is null.
select atan(null);Example: table data
Calculate the arctangent based on the Sample data. Sample statement:
select atan(bigint_data) as bigint_new, atan(double_data) as double_new, atan(decimal_data) as decimal_new, atan(string_data) as string_new from mf_math_fun_t;The following result is returned:
+---------------------+----------------------+----------------------+---------------------+
| bigint_new | double_new | decimal_new | string_new |
+---------------------+----------------------+----------------------+---------------------+
| -1.4711276743037347 | 0.483447001567199 | 0.483447001567199 | 1.4711276743037347 |
| NULL | -0.09966865249116204 | -0.09966865249116204 | -1.4711276743037347 |
| -0.7853981633974483 | NULL | 1.521935491607842 | 1.5374753309166493 |
| 1.3258176636680326 | 0.7272626879966904 | NULL | -1.5374753309166493 |
| -1.550798992821746 | -0.7853981633974483 | -0.7853981633974483 | 1.550798992821746 |
| 1.4056476493802699 | 0.982793723247329 | 0.982793723247329 | -1.550798992821746 |
| -1.5565115842075 | -1.4382447944982226 | -1.4382447944982226 | NULL |
| 0.7853981633974483 | -1.473069419436178 | -1.473069419436178 | -0.7853981633974483 |
| -1.5596856728972892 | 1.2010277920014796 | 1.2010277920014796 | 0.0 |
| 1.4711276743037347 | -1.4000611153196139 | -1.4000611153196139 | -1.5596856728972892 |
+---------------------+----------------------+----------------------+---------------------+Related functions
ATAN is a mathematical function. For more information about functions related to data computing and conversion, see Mathematical functions.