removed label weights support

Author: manishamde

mllib/src/main/scala/org/apache/spark/mllib/tree/DecisionTree.scala

@@ -259,37 +259,6 @@ object DecisionTree extends Serializable with Logging {
     new DecisionTree(strategy).train(input)
   }
 
-
-  /**
-   * Method to train a decision tree model where the instances are represented as an RDD of
-   * (label, features) pairs. The method supports binary classification and regression. For the
-   * binary classification, the label for each instance should either be 0 or 1 to denote the two
-   * classes.
-   *
-   * @param input input RDD of [[org.apache.spark.mllib.regression.LabeledPoint]] used as
-   *              training data
-   * @param algo algorithm, classification or regression
-   * @param impurity impurity criterion used for information gain calculation
-   * @param maxDepth maxDepth maximum depth of the tree
-   * @param numClassesForClassification number of classes for classification. Default value of 2.
-   * @param labelWeights A map storing weights for each label to handle unbalanced
-   *                     datasets. For example, an entry (n -> k) implies the a weight of k is
-   *                     applied to an instance with label n. It's important to note that labels
-   *                     are zero-index and take values 0, 1, 2, ... , numClasses - 1.
-   * @return a DecisionTreeModel that can be used for prediction
-   */
-  def train(
-      input: RDD[LabeledPoint],
-      algo: Algo,
-      impurity: Impurity,
-      maxDepth: Int,
-      numClassesForClassification: Int,
-      labelWeights: Map[Int,Int]): DecisionTreeModel = {
-    val strategy = new Strategy(algo, impurity, maxDepth, numClassesForClassification,
-      labelWeights = labelWeights)
-    new DecisionTree(strategy).train(input)
-  }
-
   /**
    * Method to train a decision tree model where the instances are represented as an RDD of
    * (label, features) pairs. The decision tree method supports binary classification and
@@ -303,10 +272,6 @@ object DecisionTree extends Serializable with Logging {
    * @param impurity criterion used for information gain calculation
    * @param maxDepth  maximum depth of the tree
    * @param numClassesForClassification number of classes for classification. Default value of 2.
-   * @param labelWeights A map storing weights applied to each label for handling unbalanced
-   *                     datasets. For example, an entry (n -> k) implies the a weight of k is
-   *                     applied to an instance with label n. It's important to note that labels
-   *                     are zero-index and take values 0, 1, 2, ... , numClasses - 1.
    * @param maxBins maximum number of bins used for splitting features
    * @param quantileCalculationStrategy  algorithm for calculating quantiles
    * @param categoricalFeaturesInfo A map storing information about the categorical variables and
@@ -322,12 +287,11 @@ object DecisionTree extends Serializable with Logging {
       impurity: Impurity,
       maxDepth: Int,
       numClassesForClassification: Int,
-      labelWeights: Map[Int,Int],
       maxBins: Int,
       quantileCalculationStrategy: QuantileStrategy,
       categoricalFeaturesInfo: Map[Int,Int]): DecisionTreeModel = {
     val strategy = new Strategy(algo, impurity, maxDepth, numClassesForClassification, maxBins,
-      quantileCalculationStrategy, categoricalFeaturesInfo, labelWeights = labelWeights)
+      quantileCalculationStrategy, categoricalFeaturesInfo)
     new DecisionTree(strategy).train(input)
   }
 
@@ -442,8 +406,6 @@ object DecisionTree extends Serializable with Logging {
     logDebug("numBins = " + numBins)
     val numClasses = strategy.numClassesForClassification
     logDebug("numClasses = " + numClasses)
-    val labelWeights = strategy.labelWeights
-    logDebug("labelWeights = " + labelWeights)
     val isMulticlassClassification = strategy.isMulticlassClassification
     logDebug("isMulticlassClassification = " + isMulticlassClassification)
     val isMulticlassClassificationWithCategoricalFeatures
@@ -647,7 +609,7 @@ object DecisionTree extends Serializable with Logging {
       val aggIndex = aggShift + numClasses * featureIndex * numBins
         + arr(arrIndex).toInt * numClasses
       val labelInt = label.toInt
-      agg(aggIndex + labelInt) = agg(aggIndex + labelInt) + labelWeights.getOrElse(labelInt, 1)
+      agg(aggIndex + labelInt) = agg(aggIndex + labelInt) + 1
     }
 
     def updateBinForUnorderedFeature(nodeIndex: Int, featureIndex: Int, arr: Array[Double],
@@ -667,10 +629,10 @@ object DecisionTree extends Serializable with Logging {
         val labelInt = label.toInt
         if (bins(featureIndex)(binIndex).highSplit.categories.contains(labelInt)) {
           agg(aggIndex + binIndex)
-            = agg(aggIndex + binIndex) + labelWeights.getOrElse(labelInt, 1)
+            = agg(aggIndex + binIndex) + 1
         } else {
           agg(rightChildShift + aggIndex + binIndex)
-            = agg(rightChildShift + aggIndex + binIndex) + labelWeights.getOrElse(labelInt, 1)
+            = agg(rightChildShift + aggIndex + binIndex) + 1
         }
         binIndex += 1
       }

mllib/src/main/scala/org/apache/spark/mllib/tree/configuration/Strategy.scala

@@ -39,10 +39,6 @@ import org.apache.spark.mllib.tree.configuration.QuantileStrategy._
  *                                zero-indexed.
  * @param maxMemoryInMB maximum memory in MB allocated to histogram aggregation. Default value is
  *                      128 MB.
- * @param labelWeights A map storing weights applied to each label for handling unbalanced
- *                     datasets. For example, an entry (n -> k) implies the a weight of k is
- *                     applied to an instance with label n. It's important to note that labels
- *                     are zero-index and take values 0, 1, 2, ... , numClasses.
  *
  */
 @Experimental
@@ -54,8 +50,7 @@ class Strategy (
     val maxBins: Int = 100,
     val quantileCalculationStrategy: QuantileStrategy = Sort,
     val categoricalFeaturesInfo: Map[Int, Int] = Map[Int, Int](),
-    val maxMemoryInMB: Int = 128,
-    val labelWeights: Map[Int, Int] = Map[Int, Int]()) extends Serializable {
+    val maxMemoryInMB: Int = 128) extends Serializable {
 
   require(numClassesForClassification >= 2)
   val isMulticlassClassification = numClassesForClassification > 2