series_not_equals

This page explains how to use the series_not_equals function in APL.

The series_not_equals function compares two numeric arrays element by element and returns a new array of Boolean values. Each element in the output array indicates whether the corresponding elements in the input arrays are not equal.

You use this function when you want to detect differences between two time series or arrays of values. It is particularly useful when analyzing request patterns, response times, or service traces, where identifying mismatches across parallel series matters.

For users of other query languages

If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.

Splunk SPL users

In Splunk SPL, you typically compare fields directly with the != operator. In APL, series_not_equals applies this logic to arrays, returning an array of Boolean values instead of a single Boolean.

Splunk example

... | eval is_different = if(fieldA != fieldB, 1, 0)

ANSI SQL users

In ANSI SQL, comparisons with <> return a single Boolean for each row. APL’s series_not_equals function extends this idea to arrays, producing a series of Boolean values instead of a single Boolean.

SQL example

SELECT fieldA <> fieldB AS is_different
FROM my_table

Usage

Syntax

series_not_equals(series1, series2)

Parameters

Parameter	Type	Description
series1	dynamic (array)	The first numeric array to compare.
series2	dynamic (array)	The second numeric array to compare. Must have the same length as series1.

Returns

A dynamic array of Boolean values. Each element is true if the corresponding elements in the input arrays are not equal, and false otherwise.

Use case examples

Log analysis

You can use series_not_equals to identify differences in request durations across two groups of HTTP requests.

Query

['sample-http-logs']
| summarize durations1 = make_list(req_duration_ms) by method
| join (
    ['sample-http-logs']
    | summarize durations2 = make_list(req_duration_ms) by method
) on method
| extend diff_flags = series_not_equals(durations1, durations2)

Run in Playground

Output

method	diff_flags
GET	[false,true,false]
POST	[true,false,true]

This query builds two lists of request durations grouped by method, compares them element by element, and returns an array showing where values differ.

List of related functions

• series_greater_equals: Compares two arrays and returns true when elements in the first array are greater than or equal to the second array.
• series_greater: Compares two arrays and returns true where the first array element is greater than the second.
• series_less: Compares two arrays and returns true where the first array element is less than the second.
• series_less_equals: Compares two arrays and returns true where the first array element is less than or equal to the second.