COT命令格式、参数和返回值_云原生大数据计算服务 MaxCompute(MaxCompute)-阿里云帮助中心

计算number的余切函数，输入为弧度值。

命令格式

double|decimal cot(<number>)

参数说明

number：必填。DOUBLE或DECIMAL类型。输入为STRING、BIGINT类型时，会隐式转换为DOUBLE类型后参与运算。

返回值说明

返回DOUBLE或DECIMAL类型。返回规则如下：

number为DOUBLE、DECIMAL类型时会返回相应的类型。
number为STRING、BIGINT类型时，返回DOUBLE类型。
number值为NULL时，返回NULL。

示例数据

为便于理解各函数的使用方法，本文为您提供源数据，基于源数据提供函数相关示例。创建表mf_math_fun_t，并添加数据，命令示例如下。

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');

查询表mf_math_fun_t中的数据，命令示例如下：

select * from mf_math_fun_t;
--返回结果。
+------------+-------------+-------------+--------------+------------+-------------+
| 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         |
| 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         |
+------------+-------------+-------------+--------------+------------+-------------+

使用示例：静态数据示例

--返回2.6794896585028643E-8。
select cot(3.1415926/2);
--返回NULL。
select cot(null);

使用示例：表数据示例

基于示例数据，计算余切值，命令示例如下。

selectcot(bigint_data)asbigint_new,cot(double_data)asdouble_new,cot(decimal_data)asdecimal_new,cot(string_data)asstring_newfrommf_math_fun_t;

返回结果如下。

+-----------------------+--------------------+--------------------+----------------------+
| bigint_new            | double_new         | decimal_new        | string_new           |
+-----------------------+--------------------+--------------------+----------------------+
| -1.54235104535692     | 1.7264594764178474 | 1.7264594764178474 | 1.54235104535692     |
| NULL                  | -9.966644423259238 | -9.966644423259238 | -1.54235104535692    |
| -0.6420926159343308   | NULL               | -0.02965644140592836| -0.15611995216165922|
| 0.8636911544506167    | 0.8099792954471944 | NULL               | 0.15611995216165922  |
| 3.6778144508505695    | -0.6420926159343308| -0.6420926159343308| -3.6778144508505695  |
| -3.436353004180128    | 0.07091484430265245| 0.07091484430265245| 3.6778144508505695   |
| -0.8183574478651038   | -0.36954725630901636| -0.36954725630901636| NULL               |
| 0.6420926159343308    | -1.0205622016180353 | -1.0205622016180353 | -0.6420926159343308|
| 0.5012027833801532    | -1.5893944776331337 | -1.5893944776331337 | 1.0                |
| 1.54235104535692      | 1.9059736612916494  | 1.9059736612916494  | 0.5012027833801532 |
+-----------------------+---------------------+---------------------+--------------------+