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percentrank_tdigest()

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Calculates the approximate rank of the value in a set, where rank is expressed as a percentage of the set's size. This function can be viewed as the inverse of the percentile.

Syntax

percentrank_tdigest(TDigest, Expr)

Arguments

  • TDigest: Expression that was generated by tdigest() or tdigest_merge().
  • Expr: Expression representing a value to be used for percentage ranking calculation.

Returns

The percentage rank of value in a dataset.

Tips

  1. The type of second parameter and the type of the elements in the tdigest should be the same.

  2. First parameter should be TDigest that was generated by tdigest() or tdigest_merge()

Examples

Getting the percentrank_tdigest() of the damage property that valued 4490$ is ~85%:

StormEvents
| summarize tdigestRes = tdigest(DamageProperty)
| project percentrank_tdigest(tdigestRes, 4490)
Column1
85.0015237192293

Using percentile 85 over the damage property should give 4490$:

StormEvents
| summarize tdigestRes = tdigest(DamageProperty)
| project percentile_tdigest(tdigestRes, 85, typeof(long))
percentile_tdigest_tdigestRes
4490