共用方式為


PredictStdev (DMX)

傳回指定之資料行的預測標準差。

語法

PredictStdev(<scalar column reference>)

適用於

純量資料行。

傳回類型

<scalar column reference> 指定之類型的純量值。

備註

如果資料行參考是分隔的,PredictStdev 會傳回 0,因為不能從分隔值計算標準差。

範例

下列範例根據 TM Decision Tree 採礦模型,使用自然預測聯結以判斷個人是否可能成為腳踏車買主,也判斷預測的標準差。

SELECT
  [Bike Buyer],
  PredictStdev([Bike Buyer]) AS [Standard Deviation]
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