kurtosis()

Since 1.3.0

Calculate the kurtosis from the values in a statistical aggregate. The kurtosis is the fourth statistical moment. It is a measure of “tailedness” of a data distribution compared to a normal distribution.

Samples

Calculate the kurtosis of a sample containing the integers from 0 to 100:

SELECT kurtosis(stats_agg(data))
  FROM generate_series(0, 100) data;

This returns something like:

kurtosis
----------
1.78195

Arguments

The syntax is:

kurtosis(
  summary StatsSummary1D,
  [ method TEXT ]
) RETURNS DOUBLE PRECISION

Name	Type	Default	Required	Description
summary	StatsSummary1D	-	✔	The statistical aggregate produced by a stats_agg call
method	TEXT	sample	-	The method used for calculating the kurtosis. The two options are population and sample, which can be abbreviated to pop or samp

Returns

Column	Type	Description
kurtosis	DOUBLE PRECISION	The kurtosis of the values in the statistical aggregate