Table of Contents
6 数学函数
此处列出的所有函数均支持以下场景:
除非特别说明，数学函数支持float和integer值类型。
关于函数参数的通用说明:
函数参数使用逗号分隔
参数支持表达式
可选参数(或参数部分)通过
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| 函数 | ||
|---|---|---|
| Description | 函数特定参数 | 说明 |
| abs (value) | ||
| The absolute value (from 0) of a value. | value - 待检查值 | 例如：'3'或'-3'的绝对值均为'3' 示例: => abs(last(/主机/key))>10 |
| acos (value) | ||
| The arccosine of a value as an angle, expressed in radians. | value - 待检查值 | 值必须在-1到1之间 例如：'0.5'的反余弦值为'2.0943951' 示例: => acos(last(/主机/key)) |
| asin (value) | ||
| The arcsine of a value as an angle, expressed in radians. | value - 待检查值 | 值必须在-1到1之间 例如：'0.5'的反正弦值为'-0.523598776' 示例: => asin(last(/主机/key)) |
| atan (value) | ||
| The arctangent of a value as an angle, expressed in radians. | value - 待检查值 | 例如：'1'的反正切值为'0.785398163' 示例: => atan(last(/主机/key)) |
| atan2 (value,abscissa) | ||
| The arctangent of the ordinate (value) and abscissa coordinates specified as an angle, expressed in radians. | value - 待检查值 abscissa - 横坐标值 |
例如：纵坐标和横坐标为'1'的反正切值为'2.21429744' 示例: => atan2(last(/主机/key),2) |
| avg (<value1>,<value2>,...) | ||
| Average value of the referenced item values. | valueX - 其他函数返回的值(使用监控项历史数据) | 示例: => avg(avg(/主机/key),avg(/host2/key2)) |
| cbrt (value) | ||
| Cube root of a value. | value - 待检查值 | 例如：'64'的立方根为'4'，'63'为'3.97905721' 示例: => cbrt(last(/主机/key)) |
| ceil (value) | ||
| Round the value up to the nearest greater or equal integer. | value - 待检查值 | 例如：'2.4'向上取整为'3' 示例: => ceil(last(/主机/key)) 另见floor() |
| cos (value) | ||
| The cosine of a value, where the value is an angle expressed in radians. | value - 待检查值 | 例如：'1'的余弦值为'0.54030230586' 示例: => cos(last(/主机/key)) |
| cosh (value) | ||
| The hyperbolic cosine of a value. | value - 待检查值 | 例如：'1'的双曲余弦值为'1.54308063482' 返回实数而非科学计数法 示例: => cosh(last(/主机/key)) |
| cot (value) | ||
| The cotangent of a value, where the value is an angle, expressed in radians. | value - 待检查值 | 例如：'1'的余切值为'0.54030230586' 示例: => cot(last(/主机/key)) |
| degrees (value) | ||
| Converts a value from radians to degrees. | value - 待检查值 | 例如：'1'转换为角度值为'57.2957795' 示例: => degrees(last(/主机/key)) |
| e | ||
| Euler's number (2.718281828459045). | 示例: => e() |
|
| exp (value) | ||
| Euler's number at a power of a value. | value - 待检查值 | 例如：欧拉数的'2'次方为'7.38905609893065' 示例: => exp(last(/主机/key)) |
| expm1 (value) | ||
| Euler's number at a power of a value minus 1. | value - 待检查值 | 例如：欧拉数的'2'次方减1为'6.38905609893065' 示例: => expm1(last(/主机/key)) |
| floor (value) | ||
| Round the value down to the nearest smaller or equal integer. | value - 待检查值 | 例如：'2.6'向下取整为'2' 示例: => floor(last(/主机/key)) 另见ceil() |
| log (value) | ||
| Natural logarithm. | value - 待检查值 | 例如：'2'的自然对数为'0.69314718055994529' 示例: => log(last(/主机/key)) |
| log10 (value) | ||
| Decimal logarithm. | value - 待检查值 | 例如：'5'的常用对数为'0.69897000433' 示例: => log10(last(/主机/key)) |
| max (<value1>,<value2>,...) | ||
| Highest value of the referenced item values. | valueX - 其他函数返回的值(使用监控项历史数据) | 示例: => max(avg(/主机/key),avg(/host2/key2)) |
| min (<value1>,<value2>,...) | ||
| Lowest value of the referenced item values. | valueX - 其他函数返回的值(使用监控项历史数据) | 示例: => min(avg(/主机/key),avg(/host2/key2)) |
| mod (value,denominator) | ||
| Division remainder. | value - 待检查值 denominator - 除数 |
例如：'5'除以'2'的余数为'1' 示例: => mod(last(/主机/key),2) |
| pi | ||
| Pi constant (3.14159265358979). | 示例: => pi() |
|
| power (value,power value) | ||
| The power of a value. | value - 待检查值 power value - N次方值 |
例如：'2'的3次方为'8' 示例: => power(last(/主机/key),3) |
| radians (value) | ||
| Convert a value from degrees to radians. | value - 待检查值 | 例如：'1'转换为弧度值为'0.0174532925' 示例: => radians(last(/主机/key)) |
| rand | ||
| Return a random integer value. | 使用时间作为种子生成的伪随机数(适用于数学用途，不适用于加密) 示例: => rand() |
|
| round (value,decimal places) | ||
| Round the value to decimal places. | value - 待检查值 decimal places - 指定小数位数(可为0) |
例如：'2.5482'四舍五入到2位小数为'2.55' 示例: => round(last(/主机/key),2) |
| signum (value) | ||
| Returns '-1' if a value is negative, '0' if a value is zero, '1' if a value is positive. | value - 待检查值 | 示例: => signum(last(/主机/key)) |
| sin (value) | ||
| The sine of a value, where the value is an angle expressed in radians. | value - 待检查值 | 例如：'1'的正弦值为'0.8414709848' 示例: => sin(last(/主机/key)) |
| sinh (value) | ||
| The hyperbolical sine of a value. | value - 待检查值 | 例如：'1'的双曲正弦值为'1.17520119364' 示例: => sinh(last(/主机/key)) |
| sqrt (value) | ||
| Square root of a value. | value - 待检查值 | 负值会导致函数失败 例如：'3.5'的平方根为'1.87082869339' 示例: => sqrt(last(/主机/key)) |
| sum (<value1>,<value2>,...) | ||
| Sum of the referenced item values. | valueX - 其他函数返回的值(使用监控项历史数据) | 示例: => sum(avg(/主机/key),avg(/host2/key2)) |
| tan (value) | ||
| The tangent of a value. | value - 待检查值 | 例如：'1'的正切值为'1.55740772465' 示例: => tan(last(/主机/key)) |
| truncate (value,decimal places) | ||
| Truncate the value to decimal places. | value - 待检查值 decimal places - 指定截断小数位数(可为0) |
示例: => truncate(last(/主机/key),2) |