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