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KURT.P OpenBI

How heavy the tails of a column's numbers are when they are all there is: the population excess kurtosis.

Excess kurtosis compares the tails with a normal distribution's, which scores 0: positive means more values far out than a bell curve would have, negative fewer (a flat, even spread).

Group: Aggregation. OpenBI’s own: DAX has no function of this name.

Syntax

KURT.P ( <ColumnName> )
ParameterTypeDescription
ColumnNameColumnA column of numbers.

Returns

Number. The population excess kurtosis of the column's values in the filter context; BLANK for fewer than two values, or when they are all equal.

Remarks

  • The population excess kurtosis: n × s4 ÷ s2² − 3, where s2 and s4 add up the squared and fourth powers of the differences from the mean. Excel has no function for it; it is SciPy's kurtosis with bias=True and type 1 of R's e1071 package.
  • Blanks are left out. Fewer than two values, or values that are all the same, give BLANK.
  • It never goes below −2: two values far apart are the flattest spread there is.

Compared with DAX

An OpenBI function: DAX has none like it, so a measure or query that uses it works in OpenBI only, not in Power BI or Analysis Services.

Excel has KURT (the sample's, KURT.S here) but no population kurtosis.

Examples

The prices per liter, both ways

EVALUATE
ROW (
    "Population", KURT.P ( Products[Price per liter] ),
    "Sample", KURT.S ( Products[Price per liter] )
)
PopulationSample
-1.47833910034602-2.08754325259515

The monthly liters

EVALUATE
ROW ( "Excess kurtosis", KURT.P ( Sales[Liters] ) )
Excess kurtosis
3.97558594032197

KURT.S, KURTX.P, SKEW.P, STDEV.P.

Last updated · OpenBI Studio 0.3.78