kurtosis
Computes the kurtosis of all observations.
Returns Double.NaN if fewer than 4 observations have been added. Returns -3.0 (excess) or 0.0 (non-excess) if the variance is zero (constant data).
Return
the kurtosis, or Double.NaN if insufficient data.
Parameters
kind
whether to compute sample-adjusted or population kurtosis. Defaults to PopulationKind.SAMPLE.
excess
whether to subtract 3 (the kurtosis of a normal distribution). Defaults to true.