SKEWX.P OpenBI
How lopsided an expression's results over a table's rows are, when they are all there is: the population skewness.
Skewness says which way the values lean: 0 for a symmetric spread, positive when a few large values make a long tail to the right (most order sizes, most prices), negative for a long tail to the left.
Group: Aggregation. OpenBI’s own: DAX has no function of this name.
Syntax
SKEWX.P ( <table>, <expression> )| Parameter | Type | Description |
|---|---|---|
table | Table | The rows to go through. |
expression | Expression evaluated for each row | The number worked out for each row. |
Returns
Number. The population skewness of the results; BLANK for fewer than three, or when they are all equal.
Remarks
- The population skewness, the one Excel's
SKEW.Pgives: the mean of the cubed differences from the mean, divided by the population standard deviation cubed - √n × s3 ÷ s2^1.5, where s2 and s3 add up the squared and cubed differences of the n values from their mean. - Rows where the expression is blank are left out; fewer than three results, or results that are all the same, give BLANK.
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's SKEW.P gives the same number for the same values.
Examples
Eight values
Their mean is 5; the 7 and 9 reach further above it than the 2 reaches below.
EVALUATE
ROW ( "Skewness", SKEWX.P ( DATATABLE ( "Value", INTEGER, { { 2 }, { 4 }, { 4 }, { 4 }, { 5 }, { 5 }, { 7 }, { 9 } } ), [Value] ) )| Skewness |
|---|
| 0.65625 |
Values that are all the same
EVALUATE
ROW ( "Skewness", SKEWX.P ( DATATABLE ( "Value", INTEGER, { { 5 }, { 5 }, { 5 } } ), [Value] ) )| Skewness |
|---|
| (blank) |