Documentation
Table of Contents
1 Aggregate functions
All functions listed here are supported in:
Aggregate functions can work with either:
- history of items, for example,
min(/host/key,1h) - foreach functions as the only parameter, for example,
min(last_foreach(/*/key))
Some general notes on function parameters:
- Function parameters are separated by a comma
- Optional function parameters (or parameter parts) are indicated by
<> - Function-specific parameters are described with each function
/host/keyand(sec|#num)<:time shift>parameters must never be quoted
Common parameters
/host/keyis a common mandatory first parameter for the functions referencing the host item history(sec|#num)<:time shift>is a common second parameter for the functions referencing the host item history, where:- sec - maximum evaluation period in seconds (time suffixes can be used), or
- #num - maximum evaluation range in latest collected values (if preceded by a hash mark)
- time shift (optional) allows to move the evaluation point back in time. See more details on specifying time shift.
Aggregate functions
| FUNCTION | |||
|---|---|---|---|
| Description | Function-specific parameters | Comments | |
| avg (/host/key,(sec|#num)<:time shift>) | |||
| Average value of an item within the defined evaluation period. | See common parameters. | Supported value types: float, int Examples: => avg(/host/key,1h) → average value for the last hour until now => avg(/host/key,1h:now-1d) → average value for an hour from 25 hours ago to 24 hours ago from now => avg(/host/key,#5) → average value of the five latest values => avg(/host/key,#5:now-1d) → average value of the five latest values excluding the values received in the last 24 hours Time shift is useful when there is a need to compare the current average value with the average value some time ago. |
|
| kurtosis (/host/key,(sec|#num)<:time shift>) | |||
| "Tailedness" of the probability distribution in collected values within the defined evaluation period. See also: Kurtosis |
See common parameters. | Supported value types: float, int Example: => kurtosis(/host/key,1h) → kurtosis for the last hour until now |
|
| mad (/host/key,(sec|#num)<:time shift>) | |||
| Median absolute deviation in collected values within the defined evaluation period. See also: Median absolute deviation |
See common parameters. | Supported value types: float, int Example: => mad(/host/key,1h) → median absolute deviation for the last hour until now |
|
| max (/host/key,(sec|#num)<:time shift>) | |||
| Highest value of an item within the defined evaluation period. | See common parameters. | Supported value types: float, int Example: => max(/host/key,1h) - min(/host/key,1h) → calculate the difference between the maximum and minimum values within the last hour until now (delta of values) |
|
| min (/host/key,(sec|#num)<:time shift>) | |||
| Lowest value of an item within the defined evaluation period. | See common parameters. | Supported value types: float, int Example: => max(/host/key,1h) - min(/host/key,1h) → calculate the difference between the maximum and minimum values within the last hour until now (delta of values) |
|
| skewness (/host/key,(sec|#num)<:time shift>) | |||
| Asymmetry of the probability distribution in collected values within the defined evaluation period. See also: Skewness |
See common parameters. | Supported value types: float, int Example: => skewness(/host/key,1h) → skewness for the last hour until now |
|
| stddevpop (/host/key,(sec|#num)<:time shift>) | |||
| Population standard deviation in collected values within the defined evaluation period. See also: Standard deviation |
See common parameters. | Supported value types: float, int Example: => stddevpop(/host/key,1h) → population standard deviation for the last hour until now |
|
| stddevsamp (/host/key,(sec|#num)<:time shift>) | |||
| Sample standard deviation in collected values within the defined evaluation period. See also: Standard deviation |
See common parameters. | Supported value types: float, int At least two data values are required for this function to work. Example: => stddevsamp(/host/key,1h) → sample standard deviation for the last hour until now |
|
| sum (/host/key,(sec|#num)<:time shift>) | |||
| Sum of collected values within the defined evaluation period. | See common parameters. | Supported value types: float, int Example: => sum(/host/key,1h) → sum of values for the last hour until now |
|
| sumofsquares (/host/key,(sec|#num)<:time shift>) | |||
| The sum of squares in collected values within the defined evaluation period. | See common parameters. | Supported value types: float, int Example: => sumofsquares(/host/key,1h) → sum of squares for the last hour until now |
|
| varpop (/host/key,(sec|#num)<:time shift>) | |||
| Population variance of collected values within the defined evaluation period. See also: Variance |
See common parameters. | Supported value types: float, int Example: => varpop(/host/key,1h) → population variance for the last hour until now |
|
| varsamp (/host/key,(sec|#num)<:time shift>) | |||
| Sample variance of collected values within the defined evaluation period. See also: Variance |
See common parameters. | Supported value types: float, int At least two data values are required for this function to work. Example: => varsamp(/host/key,1h) → sample variance for the last hour until now |
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