percentile_tdigest()

Learn how to use the percentile_tdigest() function to calculate the percentile value of an expression.

Calculates the percentile result from the tdigest results (which was generated by tdigest() or tdigest_merge())

Syntax

percentile_tdigest(expr, percentile [, typeLiteral])

Parameters

NameTypeRequiredDescription
exprdynamic✔️An expression that was generated by tdigest or tdigest_merge().
percentilereal✔️The value that specifies the percentile.
typeLiteralstringA type literal. If provided, the result set will be of this type. For example, typeof(long) will cast all results to type long.

Returns

The percentile value of each value in expr.

Examples

The examples in this section show how to use the syntax to help you get started.

Maximum damage by state

This query aims to find the maximum property damage caused by storm events in each state.

StormEvents
| summarize tdigestRes = tdigest(DamageProperty) by State
| project percentile_tdigest(tdigestRes, 100)

Output

percentile_tdigest_tdigestRes
0
62000000
110000000
1200000
250000

Maximum damage and latest end time by state

This query aims to find the maximum property damage and the latest end time of storm events in each state.

StormEvents
| summarize tdigestRes = tdigest(DamageProperty) by State
| union (StormEvents | summarize tdigestRes = tdigest(EndTime) by State)
| project percentile_tdigest(tdigestRes, 100)

Output

percentile_tdigest_tdigestRes
[0]
[62000000]
[“2007-12-20T11:30:00.0000000Z”]
[“2007-12-31T23:59:00.0000000Z”]