series_stats_dynamic

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

The series_stats_dynamic function computes comprehensive statistical measures for a numeric dynamic array (series), returning results in a dynamic object format with named properties. This provides the same statistics as series_stats but with more convenient access through property names instead of array indices.

You can use series_stats_dynamic when you need statistical summaries with easier property-based access, better code readability, or when integrating with other dynamic data structures. This is particularly useful in complex analytical workflows where referring to statistics by name (stats.min, stats.avg) is clearer than using array indices.

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 use multiple stats functions and store results as separate fields. In APL, series_stats_dynamic provides all statistics in a dynamic object that you can access by property names.

Splunk example

... | stats min(value) as min_val, max(value) as max_val, 
    avg(value) as avg_val, stdev(value) as stdev_val by user

ANSI SQL users

In SQL, you calculate statistics separately and work with individual columns. In APL, series_stats_dynamic provides all statistics in a single dynamic object with named properties that you can query and transform.

SQL example

SELECT 
    user_id,
    MIN(value) as min_val,
    MAX(value) as max_val,
    AVG(value) as avg_val,
    STDDEV(value) as std_val
FROM measurements
GROUP BY user_id;

Usage

Syntax

series_stats_dynamic(array)

Parameters

Parameter	Type	Description
array	dynamic	A dynamic array of numeric values.

Returns

A dynamic object containing the following statistical properties:

Property	Description
min	The minimum value in the input array.
min_idx	The first position of the minimum value in the array.
max	The maximum value in the input array.
max_idx	The first position of the maximum value in the array.
avg	The average value of the input array.
variance	The sample variance of the input array.
stdev	The sample standard deviation of the input array.

Use case examples

Log analysis

In log analysis, you can use series_stats_dynamic to generate comprehensive statistical reports with readable property names.

Query

['sample-http-logs']
| summarize durations = make_list(req_duration_ms) by id
| extend stats = series_stats_dynamic(durations)
| extend performance_score = 100 - (stats.stdev / stats.avg * 100)
| project id, 
    min = stats.min,
    max = stats.max,
    avg = stats.avg,
    performance_score
| take 5

Run in Playground

Output

id	min	max	avg	performance_score
u123	15	245	95	52.4
u456	8	189	78	50.4

This query uses property names to access statistics and calculate a custom performance score based on the coefficient of variation.

List of related functions

• series_stats: Returns the same statistics as a 7-element array instead of a dynamic object with named properties.
• series_max: Compares two arrays element-wise and returns the maximum values.
• series_min: Compares two arrays element-wise and returns the minimum values.
• todynamic: Converts values to dynamic type for custom object construction.