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| |
| ## 算数运算符和函数 |
| |
| ### 算数运算符 |
| |
| #### 一元算数运算符 |
| |
| 支持的运算符：`+`, `-` |
| |
| 输入数据类型要求：`INT32`, `INT64`, `FLOAT`, `DOUBLE` |
| |
| 输出数据类型：与输入数据类型一致 |
| |
| #### 二元算数运算符 |
| |
| 支持的运算符：`+`, `-`, `*`, `/`, `%` |
| |
| 输入数据类型要求：`INT32`, `INT64`, `FLOAT`和`DOUBLE` |
| |
| 输出数据类型：`DOUBLE` |
| |
| 注意：当某个时间戳下左操作数和右操作数都不为空（`null`）时，二元运算操作才会有输出结果 |
| |
| #### 使用示例 |
| |
| 例如： |
| |
| ```sql |
| select s1, - s1, s2, + s2, s1 + s2, s1 - s2, s1 * s2, s1 / s2, s1 % s2 from root.sg.d1 |
| ``` |
| |
| 结果： |
| |
| ``` |
| +-----------------------------+-------------+--------------+-------------+-------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+ |
| | Time|root.sg.d1.s1|-root.sg.d1.s1|root.sg.d1.s2|root.sg.d1.s2|root.sg.d1.s1 + root.sg.d1.s2|root.sg.d1.s1 - root.sg.d1.s2|root.sg.d1.s1 * root.sg.d1.s2|root.sg.d1.s1 / root.sg.d1.s2|root.sg.d1.s1 % root.sg.d1.s2| |
| +-----------------------------+-------------+--------------+-------------+-------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+ |
| |1970-01-01T08:00:00.001+08:00| 1.0| -1.0| 1.0| 1.0| 2.0| 0.0| 1.0| 1.0| 0.0| |
| |1970-01-01T08:00:00.002+08:00| 2.0| -2.0| 2.0| 2.0| 4.0| 0.0| 4.0| 1.0| 0.0| |
| |1970-01-01T08:00:00.003+08:00| 3.0| -3.0| 3.0| 3.0| 6.0| 0.0| 9.0| 1.0| 0.0| |
| |1970-01-01T08:00:00.004+08:00| 4.0| -4.0| 4.0| 4.0| 8.0| 0.0| 16.0| 1.0| 0.0| |
| |1970-01-01T08:00:00.005+08:00| 5.0| -5.0| 5.0| 5.0| 10.0| 0.0| 25.0| 1.0| 0.0| |
| +-----------------------------+-------------+--------------+-------------+-------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+ |
| Total line number = 5 |
| It costs 0.014s |
| ``` |
| |
| ### 数学函数 |
| |
| 目前 IoTDB 支持下列数学函数，这些数学函数的行为与这些函数在 Java Math 标准库中对应实现的行为一致。 |
| |
| | 函数名 | 输入序列类型 | 输出序列类型 | Java 标准库中的对应实现 | |
| | ------- | ------------------------------ | ------------------------ | ------------------------------------------------------------ | |
| | SIN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#sin(double) | |
| | COS | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#cos(double) | |
| | TAN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#tan(double) | |
| | ASIN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#asin(double) | |
| | ACOS | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#acos(double) | |
| | ATAN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#atan(double) | |
| | SINH | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#sinh(double) | |
| | COSH | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#cosh(double) | |
| | TANH | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#tanh(double) | |
| | DEGREES | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#toDegrees(double) | |
| | RADIANS | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#toRadians(double) | |
| | ABS | INT32 / INT64 / FLOAT / DOUBLE | 与输入序列的实际类型一致 | Math#abs(int) / Math#abs(long) /Math#abs(float) /Math#abs(double) | |
| | SIGN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#signum(double) | |
| | CEIL | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#ceil(double) | |
| | FLOOR | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#floor(double) | |
| | ROUND | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#rint(double) | |
| | EXP | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#exp(double) | |
| | LN | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#log(double) | |
| | LOG10 | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#log10(double) | |
| | SQRT | INT32 / INT64 / FLOAT / DOUBLE | DOUBLE | Math#sqrt(double) | |
| |
| 例如： |
| |
| ``` sql |
| select s1, sin(s1), cos(s1), tan(s1) from root.sg1.d1 limit 5 offset 1000; |
| ``` |
| |
| 结果： |
| |
| ``` |
| +-----------------------------+-------------------+-------------------+--------------------+-------------------+ |
| | Time| root.sg1.d1.s1|sin(root.sg1.d1.s1)| cos(root.sg1.d1.s1)|tan(root.sg1.d1.s1)| |
| +-----------------------------+-------------------+-------------------+--------------------+-------------------+ |
| |2020-12-10T17:11:49.037+08:00|7360723084922759782| 0.8133527237573284| 0.5817708713544664| 1.3980636773094157| |
| |2020-12-10T17:11:49.038+08:00|4377791063319964531|-0.8938962705202537| 0.4482738644511651| -1.994085181866842| |
| |2020-12-10T17:11:49.039+08:00|7972485567734642915| 0.9627757585308978|-0.27030138509681073|-3.5618602479083545| |
| |2020-12-10T17:11:49.040+08:00|2508858212791964081|-0.6073417341629443| -0.7944406950452296| 0.7644897069734913| |
| |2020-12-10T17:11:49.041+08:00|2817297431185141819|-0.8419358900502509| -0.5395775727782725| 1.5603611649667768| |
| +-----------------------------+-------------------+-------------------+--------------------+-------------------+ |
| Total line number = 5 |
| It costs 0.008s |
| ``` |
| |
