improve doc

Wayne Zhang · Wayne Zhang · commit 147311ba34db · 2017-05-19T00:00:20.000-07:00
diff --git a/mllib/src/main/scala/org/apache/spark/ml/feature/RFormula.scala b/mllib/src/main/scala/org/apache/spark/ml/feature/RFormula.scala
@@ -46,6 +46,8 @@ private[feature] trait RFormulaBase extends HasFeaturesCol with HasLabelCol {
    *   - 'alphabetDesc': descending alphabetical order
    *   - 'alphabetAsc': ascending alphabetical order
    * Default is 'frequencyDesc'.
+   * When the ordering is set to 'alphabetDesc', `RFormula` drops the same category as R
+   * when encoding strings.
    *
    * @group param
    */

Original file line number	Diff line number	Diff line change
`@@ -46,6 +46,8 @@ private[feature] trait RFormulaBase extends HasFeaturesCol with HasLabelCol {`
`46`	`46`	`* - 'alphabetDesc': descending alphabetical order`
`47`	`47`	`* - 'alphabetAsc': ascending alphabetical order`
`48`	`48`	`* Default is 'frequencyDesc'.`
	`49`	+ * When the ordering is set to 'alphabetDesc', `RFormula` drops the same category as R
	`50`	`+ * when encoding strings.`
`49`	`51`	`*`
`50`	`52`	`* @group param`
`51`	`53`	`*/`