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5 Mathematical functions
All functions listed here are supported in:
Mathematical functions are supported with float and integer value types, unless stated otherwise.
Some general notes on function parameters:
- Function parameters are separated by a comma
- Expressions are accepted as parameters
- Optional function parameters (or parameter parts) are indicated by
<>
| FUNCTION | |||
|---|---|---|---|
| Description | Function-specific parameters | Comments | |
| abs | |||
| The amount of absolute difference between the previous and latest value. This function references change() to obtain the absolute difference (see example). |
Supported value types: float, int, str, text, log For strings returns: 0 - values are equal 1 - values differ Example: => abs(change(/host/key))>10 Absolute numeric difference will be calculated, as seen with these incoming example values ('previous' and 'latest' value = absolute difference): '1' and '5' = 4'3' and '1' = 2'0' and '-2.5' = 2.5 |
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| acos | |||
| The arccosine of a value as an angle, expressed in radians. | The value must be between -1 and 1. For example, the arccosine of a value '0.5' will be '2.0943951'. Example: => acos(last(/host/key)) |
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| asin | |||
| The arcsine of a value as an angle, expressed in radians. | The value must be between -1 and 1. For example, the arcsine of a value '0.5' will be '-0.523598776'. Example: => asin(last(/host/key)) |
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| atan | |||
| The arctangent of a value as an angle, expressed in radians. | For example, the arctangent of a value '1' will be '0.785398163'. Example: => atan(last(/host/key)) |
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| atan2 (abscissa) | |||
| The arctangent of the ordinate (exprue) and abscissa coordinates specified as an angle, expressed in radians. | For example, the arctangent of the ordinate and abscissa coordinates of a value '1' will be '2.21429744'. Example: => atan2(last(/host/key),2) |
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| avg (<value1>,<value2>,...) | |||
| Average value of the referenced item values. | valueX - value returned by one of history functions | Example: => avg(avg(/host/key),avg(/host2/key2)) |
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| cbrt | |||
| Cube root of a value. | For example, the cube root of '64' will be '4', of '63' will be '3.97905721'. Example: => cbrt(last(/host/key)) |
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| ceil | |||
| Round the value up to the nearest greater integer. | For example, '2.4' will be rounded up to '3'. Example: => ceil(last(/host/key)) See also floor(). |
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| cos | |||
| The cosine of a value, where the value is an angle expressed in radians. | For example, the cosine of a value '1' will be '0.54030230586'. Example: => cos(last(/host/key)) |
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| cosh | |||
| The hyperbolic cosine of a value. | For example, the hyperbolic cosine of a value '1' will be '1.54308063482'. Returns value as a real number, not as scientific notation. Example: => cosh(last(/host/key)) |
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| cot | |||
| The cotangent of a value, where the value is an angle, expressed in radians. | For example, the cotangent of a value '1' will be '0.54030230586'. Example: => cot(last(/host/key)) |
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| degrees | |||
| Converts a value from radians to degrees. | For example, a value '1' converted to degrees will be '57.2957795'. Example: => degrees(last(/host/key)) |
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| e | |||
| Euler's number (2.718281828459045). | Example: => e() |
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| exp | |||
| Euler's number at a power of a value. | For example, Euler's number at a power of a value '2' will be '7.38905609893065'. Example: => exp(last(/host/key)) |
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| expm1 | |||
| Euler's number at a power of a value minus 1. | For example, Euler's number at a power of a value '2' minus 1 will be '6.38905609893065'. Example: => expm1(last(/host/key)) |
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| floor | |||
| Round the value down to the nearest smaller integer. | For example, '2.6' will be rounded down to '2'. Example: => floor(last(/host/key)) See also ceil(). |
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| log | |||
| Natural logarithm. | For example, the natural logarithm of a value '2' will be '0.69314718055994529'. Example: => log(last(/host/key)) |
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| log10 | |||
| Decimal logarithm. | For example, the decimal logarithm of a value '5' will be '0.69897000433'. Example: => log10(last(/host/key)) |
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| max (<value1>,<value2>,...) | |||
| Highest value of the referenced item values. | valueX - value returned by one of history functions | Example: => max(avg(/host/key),avg(/host2/key2)) |
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| min (<value1>,<value2>,...) | |||
| Lowest value of the referenced item values. | valueX - value returned by one of history functions | Example: => min(avg(/host/key),avg(/host2/key2)) |
|
| mod (denominator) | |||
| Division remainder. | denominator - division denominator | For example, division remainder of a value '5' with division denominator '2' will be '1'. Example: => mod(last(/host/key),2) |
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| pi | |||
| Pi constant (3.14159265358979). | Example: => pi() |
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| power (power value) | |||
| The power of a value. | power value - the Nth power to use | For example, the 3rd power of a value '2' will be '8'. Example: => power(last(/host/key),3) |
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| radians | |||
| Convert a value from degrees to radians. | For example, a value '1' converted to radians will be '0.0174532925'. Example: => radians(last(/host/key)) |
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| rand | |||
| Return a random integer value. | A pseudo-random generated number using time as seed (enough for mathematical purposes, but not cryptography). Example: => rand() |
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| round (decimal places) | |||
| Round the value to decimal places. | decimal places - specify decimal places for rounding (0 is also possible) | For example, a value '2.5482' rounded to 2 decimal places will be '2.55'. Example: => round(last(/host/key),2) |
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| signum | |||
| Returns '-1' if a value is negative, '0' if a value is zero, '1' if a value is positive. | Example: => signum(last(/host/key)) |
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| sin | |||
| The sine of a value, where the value is an angle expressed in radians. | For example, the sine of a value '1' will be '0.8414709848'. Example: => sin(last(/host/key)) |
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| sinh | |||
| The hyperbolical sine of a value. | For example, the hyperbolical sine of a value '1' will be '1.17520119364'. Example: => sinh(last(/host/key)) |
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| sqrt | |||
| Square root of a value. | This function will fail with a negative value. For example, the square root of a value '3.5' will be '1.87082869339'. Example: => sqrt(last(/host/key)) |
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| sum (<value1>,<value2>,...) | |||
| Sum of the referenced item values. | valueX - value returned by one of history functions | Example: => sum(avg(/host/key),avg(/host2/key2)) |
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| tan | |||
| The tangent of a value. | For example, the tangent of a value '1' will be '1.55740772465'. Example: => tan(last(/host/key)) |
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| truncate (decimal places) | |||
| Truncate the value to decimal places. | decimal places - specify decimal places for truncating (0 is also possible) | Example: => truncate(last(/host/key),2) |
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