root
/
elasticsearch
mirror of https://github.com/elastic/elasticsearch.git
1
0
Fork 0
Code Issues Actions 1 Packages Projects Releases Wiki Activity
elasticsearch/docs/reference/esql/functions/layout/mv_median_absolute_deviatio...

16 lines
560 B
Plaintext
Raw Normal View History

ESQL: mv_median_absolute_deviation function (#112055) - Added mv_median_absolute_deviation function - Added possibility of having a fixed param in Multivalue "ascending" functions - Add surrogate to MedianAbsoluteDeviation ### Calculations used to avoid overflows First, a quick recap of how the MAD is calculated: 1. Sort values, and get the median 2. Calculate the difference between each value with the median (`abs(median - value)`) 3. Sort the differences, and get their median Calculating a MAD may overflow when calculating the differences (Step 2), given the type is a signed number, as the difference is a positive value, with potentially the same value as `POSITIVE_MAX - NEGATIVE_MIN`. To solve this, some types are up-casted as follow: - Int: Stored as longs, simple approach - Long: Stored as longs, but switched to unsigned long representation when calculating the differences - Unsigned long: No effect; the resulting range is the same - Doubles: Nothing. If the values overflow to +/-infinity, they're left that way, as we'll just use those outliers to sort Closes https://github.com/elastic/elasticsearch/issues/111590
2024-09-09 16:04:25 +08:00
// This is generated by ESQL's AbstractFunctionTestCase. Do no edit it. See ../README.md for how to regenerate it.
[discrete]
[[esql-mv_median_absolute_deviation]]
=== `MV_MEDIAN_ABSOLUTE_DEVIATION`
*Syntax*
[.text-center]
image::esql/functions/signature/mv_median_absolute_deviation.svg[Embedded,opts=inline]
include::../parameters/mv_median_absolute_deviation.asciidoc[]
include::../description/mv_median_absolute_deviation.asciidoc[]
include::../types/mv_median_absolute_deviation.asciidoc[]
include::../examples/mv_median_absolute_deviation.asciidoc[]