PredictVariance (DMX)
Returns the variance of a specified column.
Syntax
PredictVariance(<scalar column reference>)
Applies To
A scalar column.
Return Type
A scalar value of the type that is specified by <scalar column reference>.
Remarks
If the column reference is discrete, PredictVariance returns 0 because the variance cannot be calculated from discrete values.
Examples
The following example uses a natural prediction join to determine if an individual is likely to be a bike buyer based on the TM Decision Tree mining model, and also determines the variance for the prediction.
SELECT
[Bike Buyer],
PredictVariance([Bike Buyer]) AS [Variance]
FROM
[TM Decision Tree]
NATURAL PREDICTION JOIN
(SELECT 28 AS [Age],
'2-5 Miles' AS [Commute Distance],
'Graduate Degree' AS [Education],
0 AS [Number Cars Owned],
0 AS [Number Children At Home]) AS t