# Mathematical functions and operations Several tasks such as **Aggregator**, **Condition,** and **Notification** are empowered by an extended mathematical editor that supports a powerful set of mathematical functions and operations. ## Mathematical functions
Most probably you are already familiar with them and used these ones in **SQL databases**, **Microsoft Excel**, or **Google Spreadsheets**. ### Array functions | Formula | Meaning | Example | | ---------------------- | ------------------------------------- | ----------- | | **AVG(field\_name)** | Average value in the input data set | AVG(amount) | | **SUM(field\_name)** | A sum of values in the input data set | SUM(amount) | | **COUNT()** | Number of rows in the input data set | | | **FIRST(field\_name)** | First value in the input data set | | | **LAST(field\_name)** | Last value in the input data set | | | **MAX(field\_name)** | Max value in the input data set | MAX(amount) | | **MIN(field\_name)** | Min value in the input data set | MIN(amount) | ### Single number functions
FormulaMeaningExample
ROUND(field_name, precision, "floor|ceil")Round a number up or down with a certain precisionROUND(tax, 2, "floor")
ABS(field_name)The absolute value of a number
NEG(field_name)Inverts the sign of a number. From "-" to "+" and other way around
SIGN(field_name)

Returns:

-1 if d <  0
 0 if d == 0
+1 if d >  0
STRING(field_name)Converts number to string
INT(field_name)Returns an integer part of a decimal number
### Other functions | Formula | Meaning | Example | | ----------- | ----------------------------------------------------------- | ----------------------- | | **ENV()** | Use environment variable in a format of ENV\_variable\_name | ENV\_REVENUE\_THRESHOLD | | **NOW()** | Current timestamp | | | **INPUT()** | The entire input data set as JSON | | ### Metric functions Also, there's an additional set of functions available for [Metrics](https://docs.ylem.co/metrics) only:
| Formula | Meaning | Example | | ----------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------- | | **METRIC\_AVG("period", duration)** | This function returns an average value of this metric within a selected period of time |

METRIC\_AVG("day", 5)
or
METRIC\_AVG("month", 3)
etc.

| | **METRIC\_QUANTILE(level, "period", duration)** | This function returns a metric quantile within a selected period of time | METRIC\_QUANTILE(0.25, "day", 7) | | **METRIC\_MEDIAN("period", duration)** |

This function returns a median metric value within a selected period of time.

Alias for METRIC\_QUANTILE(0.5, "period", duration)

|

METRIC\_MEDIAN("day", 5)
or
METRIC\_MEDIAN("month", 3)
etc.

| ## Arithmetical and logical operations The following list is supported: ### Arithmetic +\ -\ /\ \*\ %\ \*\* ### Comparison \==\ \===\ !=\ !==\ \>\ <\ \>=\ <=\ \>==\ <== ### Boolean operators ||\ &&\ ! ### Bitmasking |\ &\ ^\ <<\ \>> ## Regular expression comparison The following two operations are supported for searching in strings with regular expressions \=\~ // means a regular expression match is found\ !\~ // means a regular expression match is not found For example, the following string placed in the Condition or Aggregator will return `true` ```regex "Mountaineering is the best sport in the world. Or engineering?" =~ "[(Engin|Mountain)]eering\\s" ``` Supported syntax for regular expressions: . ## Formatting of dates Comparison operations can also be used for comparing dates. The following formats are supported: * time.UnixDate, * time.RubyDate, * time.Kitchen, * time.RFC3339, * time.RFC3339Nano, * "2006-01-02", // RFC 3339 * "2006-01-02 15:04", // RFC 3339 with minutes * "2006-01-02 15:04:05", // RFC 3339 with seconds * "2006-01-02 15:04:05-07:00", // RFC 3339 with seconds and timezone * "2006-01-02T15Z", // ISO8601 with hour without UTC offset * "2006-01-02T15:04Z", // ISO8601 with minutes without UTC offset * "2006-01-02T15Z0700", // ISO8601 with hour * "2006-01-02T15:04:05Z", // ISO8601 with seconds without UTC offset * "2006-01-02T15:04Z0700", // ISO8601 with minutes * "2006-01-02T15:04:05Z0700", // ISO8601 with seconds * "2006-01-02T15:04:05.999999999Z", // ISO8601 with nanoseconds without UTC offset * "2006-01-02T15:04:05.999999999Z0700", // ISO8601 with nanoseconds