Github user holdenk commented on a diff in the pull request:
https://github.com/apache/spark/pull/6339#discussion_r35815819
--- Diff:
mllib/src/main/scala/org/apache/spark/ml/feature/StringIndexer.scala ---
@@ -151,4 +153,77 @@ class StringIndexerModel private[ml] (
val copied = new StringIndexerModel(uid, labels)
copyValues(copied, extra)
}
+
+ /**
+ * Return a model to perform the inverse transformation.
+ * Note: By default we keep the original columns during this
transformation, so the inverse
+ * should only be used on new columns such as predicted labels.
+ */
+ def invert(inputCol: String, outputCol: String):
StringIndexerInverseTransformer = {
+ val labelsCol: String = $(this.outputCol)
+ new StringIndexerInverseTransformer(labelsCol)
+ .setInputCol(inputCol)
+ .setOutputCol(outputCol)
+ }
+}
+
+/**
+ * :: Experimental ::
+ * Transform a provided column back to the original input types using the
metadata on the
+ * labelsCol. Note: By default we keep the original columns during this
transformation,
+ * so the inverse should only be used on new columns such as predicted
labels.
+ */
+@Experimental
+class StringIndexerInverseTransformer private[ml] (
+ override val uid: String,
+ val labelsCol: String) extends Transformer
--- End diff --
relatedly: should we add a JIRA to add the metadata in the models outputs?
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
