Remove RandomForestClassificationModelParams and RandomForestRegressi…

…onModelParams.

mllib/src/main/scala/org/apache/spark/ml/classification/GBTClassifier.scala

@@ -201,6 +201,11 @@ class GBTClassificationModel private[ml](
   @Since("1.4.0")
   override def trees: Array[DecisionTreeRegressionModel] = _trees
 
+  /**
+   * Number of trees in ensemble
+   */
+  val getNumTrees: Int = trees.length
+
   @Since("1.4.0")
   override def treeWeights: Array[Double] = _treeWeights
 

mllib/src/main/scala/org/apache/spark/ml/classification/RandomForestClassifier.scala

@@ -158,7 +158,7 @@ class RandomForestClassificationModel private[ml] (
     @Since("1.6.0") override val numFeatures: Int,
     @Since("1.5.0") override val numClasses: Int)
   extends ProbabilisticClassificationModel[Vector, RandomForestClassificationModel]
-  with RandomForestClassificationModelParams with TreeEnsembleModel[DecisionTreeClassificationModel]
+  with RandomForestClassifierParams with TreeEnsembleModel[DecisionTreeClassificationModel]
   with MLWritable with Serializable {
 
   require(_trees.nonEmpty, "RandomForestClassificationModel requires at least 1 tree.")

mllib/src/main/scala/org/apache/spark/ml/regression/GBTRegressor.scala

@@ -183,6 +183,11 @@ class GBTRegressionModel private[ml](
   @Since("1.4.0")
   override def trees: Array[DecisionTreeRegressionModel] = _trees
 
+  /**
+   * Number of trees in ensemble
+   */
+  val getNumTrees: Int = trees.length
+
   @Since("1.4.0")
   override def treeWeights: Array[Double] = _treeWeights
 

mllib/src/main/scala/org/apache/spark/ml/regression/RandomForestRegressor.scala

@@ -144,7 +144,7 @@ class RandomForestRegressionModel private[ml] (
     private val _trees: Array[DecisionTreeRegressionModel],
     override val numFeatures: Int)
   extends PredictionModel[Vector, RandomForestRegressionModel]
-  with RandomForestRegressionModelParams with TreeEnsembleModel[DecisionTreeRegressionModel]
+  with RandomForestRegressorParams with TreeEnsembleModel[DecisionTreeRegressionModel]
   with MLWritable with Serializable {
 
   require(_trees.nonEmpty, "RandomForestRegressionModel requires at least 1 tree.")

mllib/src/main/scala/org/apache/spark/ml/tree/treeModels.scala

@@ -95,11 +95,6 @@ private[ml] trait TreeEnsembleModel[M <: DecisionTreeModel] {
   /** Trees in this ensemble. Warning: These have null parent Estimators. */
   def trees: Array[M]
 
-  /**
-   * Number of trees in ensemble
-   */
-  val getNumTrees: Int = trees.length
-
   /** Weights for each tree, zippable with [[trees]] */
   def treeWeights: Array[Double]
 

mllib/src/main/scala/org/apache/spark/ml/tree/treeParams.scala

@@ -317,8 +317,28 @@ private[ml] trait TreeEnsembleParams extends DecisionTreeParams {
   }
 }
 
-/** Used for [[RandomForestParams]] */
-private[ml] trait HasFeatureSubsetStrategy extends Params {
+/**
+ * Parameters for Random Forest algorithms.
+ */
+private[ml] trait RandomForestParams extends TreeEnsembleParams {
+
+  /**
+   * Number of trees to train (>= 1).
+   * If 1, then no bootstrapping is used.  If > 1, then bootstrapping is done.
+   * TODO: Change to always do bootstrapping (simpler).  SPARK-7130
+   * (default = 20)
+   * @group param
+   */
+  final val numTrees: IntParam = new IntParam(this, "numTrees", "Number of trees to train (>= 1)",
+    ParamValidators.gtEq(1))
+
+  setDefault(numTrees -> 20)
+
+  /** @group setParam */
+  def setNumTrees(value: Int): this.type = set(numTrees, value)
+
+  /** @group getParam */
+  final def getNumTrees: Int = $(numTrees)
 
   /**
    * The number of features to consider for splits at each tree node.
@@ -364,38 +384,6 @@ private[ml] trait HasFeatureSubsetStrategy extends Params {
   final def getFeatureSubsetStrategy: String = $(featureSubsetStrategy).toLowerCase
 }
 
-/**
- * Used for [[RandomForestParams]].
- * This is separated out from [[RandomForestParams]] because of an issue with the
- * `numTrees` method conflicting with this Param in the Estimator.
- */
-private[ml] trait HasNumTrees extends Params {
-
-  /**
-   * Number of trees to train (>= 1).
-   * If 1, then no bootstrapping is used.  If > 1, then bootstrapping is done.
-   * TODO: Change to always do bootstrapping (simpler).  SPARK-7130
-   * (default = 20)
-   * @group param
-   */
-  final val numTrees: IntParam = new IntParam(this, "numTrees", "Number of trees to train (>= 1)",
-    ParamValidators.gtEq(1))
-
-  setDefault(numTrees -> 20)
-
-  /** @group setParam */
-  def setNumTrees(value: Int): this.type = set(numTrees, value)
-
-  /** @group getParam */
-  final def getNumTrees: Int = $(numTrees)
-}
-
-/**
- * Parameters for Random Forest algorithms.
- */
-private[ml] trait RandomForestParams extends TreeEnsembleParams
-  with HasFeatureSubsetStrategy with HasNumTrees
-
 private[spark] object RandomForestParams {
   // These options should be lowercase.
   final val supportedFeatureSubsetStrategies: Array[String] =
@@ -405,15 +393,9 @@ private[spark] object RandomForestParams {
 private[ml] trait RandomForestClassifierParams
   extends RandomForestParams with TreeClassifierParams
 
-private[ml] trait RandomForestClassificationModelParams extends TreeEnsembleParams
-  with HasFeatureSubsetStrategy with TreeClassifierParams
-
 private[ml] trait RandomForestRegressorParams
   extends RandomForestParams with TreeRegressorParams
 
-private[ml] trait RandomForestRegressionModelParams extends TreeEnsembleParams
-  with HasFeatureSubsetStrategy with TreeRegressorParams
-
 /**
  * Parameters for Gradient-Boosted Tree algorithms.
  *
@@ -437,7 +419,6 @@ private[ml] trait GBTParams extends TreeEnsembleParams with HasMaxIter with HasS
   /** @group setParam */
   def setMaxIter(value: Int): this.type = set(maxIter, value)
 
-
   /**
    * Step size (a.k.a. learning rate) in interval (0, 1] for shrinking the contribution of each
    * estimator.