PowerRegB (PQL)

Calculates the power regression of a set and returns the value of “b” in the regression line, y=(ax)^b

Syntax

PowerRegB( <List> , <Numeric> , OPTIONAL <Numeric> )

* Click on the function's arguments above for more details on the input values.

Comments

The PowerRegX functions calculate the power regression for the supplied values / measures, and then return one of the values associated with that regression. The power regression functions are:

Arguments

PowerRegB returns the value of b, the exponent, for the power regression, and requires the following arguments:

  • The List parameter is a list or set of elements from an existing hierarchy in the model.
    • The hierarchy name needs to be a Unique Name with the format [dimension].^[hierarchy] or [table].[column].
  • The Numeric parameters following the set are each evaluated against the specified set to obtain the values for the y- and x-axes, respectively.
    • The values can be returned from a hierarchy as a numeric expression.
    • If the optional numeric value is not supplied, the current context of the cells is used for the x-axis.
Remarks

Examples

When drawing a power regression across the last 10 date-key members, where Sales is regressed against Profit, the value of b (the exponent) is returned using the following function:

PowerRegB( Tail([Date].[dateKey].allmembers, 10), [Measures].[Fact Sales], [Measures].[Profit] )

Tip: Alternatively, use Last in place of Tail. Last and Tail are aliases for the function that retrieves the last X elements in a given hierarchy. For more information, see Tail (PQL).