Github user mengxr commented on a diff in the pull request:
https://github.com/apache/spark/pull/5530#discussion_r28626572
--- Diff: mllib/src/main/scala/org/apache/spark/ml/impl/tree/Split.scala ---
@@ -0,0 +1,105 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.ml.impl.tree
+
+import org.apache.spark.mllib.linalg.Vector
+import org.apache.spark.mllib.tree.configuration.{FeatureType =>
OldFeatureType}
+import org.apache.spark.mllib.tree.model.{Split => OldSplit}
+
+
+/**
+ * Interface for a "Split," which specifies a test made at a decision tree
node
+ * to choose the left or right path.
+ */
+trait Split extends Serializable {
+
+ /** Index of feature which this split tests */
+ def feature: Int
+
+ /** Return true (split to left) or false (split to right) */
+ private[ml] def goLeft(features: Vector): Boolean
+
+ /** Convert to old Split format */
+ private[tree] def toOld: OldSplit
+}
+
+private[ml] object Split {
+
+ def fromOld(oldSplit: OldSplit): Split = {
+ oldSplit.featureType match {
+ case OldFeatureType.Categorical =>
+ new CategoricalSplit(feature = oldSplit.feature,
+ categories = oldSplit.categories.toSet)
+ case OldFeatureType.Continuous =>
+ new ContinuousSplit(feature = oldSplit.feature, threshold =
oldSplit.threshold)
+ }
+ }
+
+}
+
+/**
+ * Split which tests a categorical feature.
+ * @param feature Index of the feature to test
+ * @param categories If the feature value is in this set of categories,
then the split goes left.
+ * Otherwise, it goes right.
+ */
+class CategoricalSplit(override val feature: Int, val categories:
Set[Double]) extends Split {
--- End diff --
Sounds good.
---
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]
