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:

  • 函数参数通过逗号分隔
  • 表达式可作为参数传递
  • 可选参数(或参数部分)通过< >标识
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 数值范围必须在-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 数值范围必须在-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 - 其他函数返回的监控项历史数据值 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'的立方根为'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'将向上取整为'3'

示例:
=> ceil(last(/主机/key))

另见floor()函数
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'

返回值为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:以'2'为指数的欧拉数为'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:以'2'为指数的欧拉数减1得'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'将向下取整为'2'

示例:
=> floor(last(/主机/key))

另见ceil()函数
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 - 其他函数返回的监控项历史数据值 示例:
=> max(avg(/主机/key),avg(/host2/key2))
min (<value1>,<value2>,...)
Lowest value of the referenced item values. valueX - 其他函数返回的监控项历史数据值 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 - 幂指数
例如:'2'的3次幂为'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,不适用于密码学)

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(支持0位)
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 负值将导致函数执行失败

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 - 其他函数返回的监控项历史数据值 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(支持0位)
示例:
=> truncate(last(/主机/key),2)