[SPARK-10265][DOCUMENTATION, ML] Fixed @Since annotation to ml.regression

Here is my first commit.

Author: Ehsan M.Kermani <ehsanmo1367@gmail.com>

Closes #8728 from ehsanmok/SinceAnn.

5 files changed, 119 insertions, 18 deletions

diff --git a/mllib/src/main/scala/org/apache/spark/ml/regression/DecisionTreeRegressor.scala b/mllib/src/main/scala/org/apache/spark/ml/regression/DecisionTreeRegressor.scala
index 88b79a4eb8..04420fc6e8 100644
--- a/mllib/src/main/scala/org/apache/spark/ml/regression/DecisionTreeRegressor.scala
+++ b/mllib/src/main/scala/org/apache/spark/ml/regression/DecisionTreeRegressor.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.ml.regression
 
-import org.apache.spark.annotation.Experimental
+import org.apache.spark.annotation.{Experimental, Since}
 import org.apache.spark.ml.{PredictionModel, Predictor}
 import org.apache.spark.ml.param.ParamMap
 import org.apache.spark.ml.tree.{DecisionTreeModel, DecisionTreeParams, Node, TreeRegressorParams}
@@ -36,30 +36,39 @@ import org.apache.spark.sql.DataFrame
  * for regression.
  * It supports both continuous and categorical features.
  */
+@Since("1.4.0")
 @Experimental
-final class DecisionTreeRegressor(override val uid: String)
+final class DecisionTreeRegressor @Since("1.4.0") (@Since("1.4.0") override val uid: String)
   extends Predictor[Vector, DecisionTreeRegressor, DecisionTreeRegressionModel]
   with DecisionTreeParams with TreeRegressorParams {
 
+  @Since("1.4.0")
   def this() = this(Identifiable.randomUID("dtr"))
 
   // Override parameter setters from parent trait for Java API compatibility.
-
+  @Since("1.4.0")
   override def setMaxDepth(value: Int): this.type = super.setMaxDepth(value)
 
+  @Since("1.4.0")
   override def setMaxBins(value: Int): this.type = super.setMaxBins(value)
 
+  @Since("1.4.0")
   override def setMinInstancesPerNode(value: Int): this.type =
     super.setMinInstancesPerNode(value)
 
+  @Since("1.4.0")
   override def setMinInfoGain(value: Double): this.type = super.setMinInfoGain(value)
 
+  @Since("1.4.0")
   override def setMaxMemoryInMB(value: Int): this.type = super.setMaxMemoryInMB(value)
 
+  @Since("1.4.0")
   override def setCacheNodeIds(value: Boolean): this.type = super.setCacheNodeIds(value)
 
+  @Since("1.4.0")
   override def setCheckpointInterval(value: Int): this.type = super.setCheckpointInterval(value)
 
+  @Since("1.4.0")
   override def setImpurity(value: String): this.type = super.setImpurity(value)
 
   override protected def train(dataset: DataFrame): DecisionTreeRegressionModel = {
@@ -78,9 +87,11 @@ final class DecisionTreeRegressor(override val uid: String)
       subsamplingRate = 1.0)
   }
 
+  @Since("1.4.0")
   override def copy(extra: ParamMap): DecisionTreeRegressor = defaultCopy(extra)
 }
 
+@Since("1.4.0")
 @Experimental
 object DecisionTreeRegressor {
   /** Accessor for supported impurities: variance */
@@ -93,6 +104,7 @@ object DecisionTreeRegressor {
  * It supports both continuous and categorical features.
  * @param rootNode  Root of the decision tree
  */
+@Since("1.4.0")
 @Experimental
 final class DecisionTreeRegressionModel private[ml] (
     override val uid: String,
@@ -115,10 +127,12 @@ final class DecisionTreeRegressionModel private[ml] (
     rootNode.predictImpl(features).prediction
   }
 
+  @Since("1.4.0")
   override def copy(extra: ParamMap): DecisionTreeRegressionModel = {
     copyValues(new DecisionTreeRegressionModel(uid, rootNode, numFeatures), extra).setParent(parent)
   }
 
+  @Since("1.4.0")
   override def toString: String = {
     s"DecisionTreeRegressionModel (uid=$uid) of depth $depth with $numNodes nodes"
   }
diff --git a/mllib/src/main/scala/org/apache/spark/ml/regression/GBTRegressor.scala b/mllib/src/main/scala/org/apache/spark/ml/regression/GBTRegressor.scala
index 65b5b3e072..07144cc7cf 100644
--- a/mllib/src/main/scala/org/apache/spark/ml/regression/GBTRegressor.scala
+++ b/mllib/src/main/scala/org/apache/spark/ml/regression/GBTRegressor.scala
@@ -20,7 +20,7 @@ package org.apache.spark.ml.regression
 import com.github.fommil.netlib.BLAS.{getInstance => blas}
 
 import org.apache.spark.Logging
-import org.apache.spark.annotation.Experimental
+import org.apache.spark.annotation.{Experimental, Since}
 import org.apache.spark.ml.{PredictionModel, Predictor}
 import org.apache.spark.ml.param.{Param, ParamMap}
 import org.apache.spark.ml.tree.{DecisionTreeModel, GBTParams, TreeEnsembleModel, TreeRegressorParams}
@@ -42,54 +42,65 @@ import org.apache.spark.sql.types.DoubleType
  * learning algorithm for regression.
  * It supports both continuous and categorical features.
  */
+@Since("1.4.0")
 @Experimental
-final class GBTRegressor(override val uid: String)
+final class GBTRegressor @Since("1.4.0") (@Since("1.4.0") override val uid: String)
   extends Predictor[Vector, GBTRegressor, GBTRegressionModel]
   with GBTParams with TreeRegressorParams with Logging {
 
+  @Since("1.4.0")
   def this() = this(Identifiable.randomUID("gbtr"))
 
   // Override parameter setters from parent trait for Java API compatibility.
 
   // Parameters from TreeRegressorParams:
-
+  @Since("1.4.0")
   override def setMaxDepth(value: Int): this.type = super.setMaxDepth(value)
 
+  @Since("1.4.0")
   override def setMaxBins(value: Int): this.type = super.setMaxBins(value)
 
+  @Since("1.4.0")
   override def setMinInstancesPerNode(value: Int): this.type =
     super.setMinInstancesPerNode(value)
 
+  @Since("1.4.0")
   override def setMinInfoGain(value: Double): this.type = super.setMinInfoGain(value)
 
+  @Since("1.4.0")
   override def setMaxMemoryInMB(value: Int): this.type = super.setMaxMemoryInMB(value)
 
+  @Since("1.4.0")
   override def setCacheNodeIds(value: Boolean): this.type = super.setCacheNodeIds(value)
 
+  @Since("1.4.0")
   override def setCheckpointInterval(value: Int): this.type = super.setCheckpointInterval(value)
 
   /**
    * The impurity setting is ignored for GBT models.
    * Individual trees are built using impurity "Variance."
    */
+  @Since("1.4.0")
   override def setImpurity(value: String): this.type = {
     logWarning("GBTRegressor.setImpurity should NOT be used")
     this
   }
 
   // Parameters from TreeEnsembleParams:
-
+  @Since("1.4.0")
   override def setSubsamplingRate(value: Double): this.type = super.setSubsamplingRate(value)
 
+  @Since("1.4.0")
   override def setSeed(value: Long): this.type = {
     logWarning("The 'seed' parameter is currently ignored by Gradient Boosting.")
     super.setSeed(value)
   }
 
   // Parameters from GBTParams:
-
+  @Since("1.4.0")
   override def setMaxIter(value: Int): this.type = super.setMaxIter(value)
 
+  @Since("1.4.0")
   override def setStepSize(value: Double): this.type = super.setStepSize(value)
 
   // Parameters for GBTRegressor:
@@ -100,6 +111,7 @@ final class GBTRegressor(override val uid: String)
    * (default = squared)
    * @group param
    */
+  @Since("1.4.0")
   val lossType: Param[String] = new Param[String](this, "lossType", "Loss function which GBT" +
     " tries to minimize (case-insensitive). Supported options:" +
     s" ${GBTRegressor.supportedLossTypes.mkString(", ")}",
@@ -108,9 +120,11 @@ final class GBTRegressor(override val uid: String)
   setDefault(lossType -> "squared")
 
   /** @group setParam */
+  @Since("1.4.0")
   def setLossType(value: String): this.type = set(lossType, value)
 
   /** @group getParam */
+  @Since("1.4.0")
   def getLossType: String = $(lossType).toLowerCase
 
   /** (private[ml]) Convert new loss to old loss. */
@@ -135,13 +149,16 @@ final class GBTRegressor(override val uid: String)
     GBTRegressionModel.fromOld(oldModel, this, categoricalFeatures, numFeatures)
   }
 
+  @Since("1.4.0")
   override def copy(extra: ParamMap): GBTRegressor = defaultCopy(extra)
 }
 
+@Since("1.4.0")
 @Experimental
 object GBTRegressor {
   // The losses below should be lowercase.
   /** Accessor for supported loss settings: squared (L2), absolute (L1) */
+  @Since("1.4.0")
   final val supportedLossTypes: Array[String] = Array("squared", "absolute").map(_.toLowerCase)
 }
 
@@ -154,6 +171,7 @@ object GBTRegressor {
  * @param _trees  Decision trees in the ensemble.
  * @param _treeWeights  Weights for the decision trees in the ensemble.
  */
+@Since("1.4.0")
 @Experimental
 final class GBTRegressionModel private[ml](
     override val uid: String,
@@ -172,11 +190,14 @@ final class GBTRegressionModel private[ml](
    * @param _trees  Decision trees in the ensemble.
    * @param _treeWeights  Weights for the decision trees in the ensemble.
    */
+  @Since("1.4.0")
   def this(uid: String, _trees: Array[DecisionTreeRegressionModel], _treeWeights: Array[Double]) =
     this(uid, _trees, _treeWeights, -1)
 
+  @Since("1.4.0")
   override def trees: Array[DecisionTreeModel] = _trees.asInstanceOf[Array[DecisionTreeModel]]
 
+  @Since("1.4.0")
   override def treeWeights: Array[Double] = _treeWeights
 
   override protected def transformImpl(dataset: DataFrame): DataFrame = {
@@ -194,11 +215,13 @@ final class GBTRegressionModel private[ml](
     blas.ddot(numTrees, treePredictions, 1, _treeWeights, 1)
   }
 
+  @Since("1.4.0")
   override def copy(extra: ParamMap): GBTRegressionModel = {
     copyValues(new GBTRegressionModel(uid, _trees, _treeWeights, numFeatures),
       extra).setParent(parent)
   }
 
+  @Since("1.4.0")
   override def toString: String = {
     s"GBTRegressionModel (uid=$uid) with $numTrees trees"
   }
diff --git a/mllib/src/main/scala/org/apache/spark/ml/regression/IsotonicRegression.scala b/mllib/src/main/scala/org/apache/spark/ml/regression/IsotonicRegression.scala
index f4a17c8f9a..a1fe01b047 100644
--- a/mllib/src/main/scala/org/apache/spark/ml/regression/IsotonicRegression.scala
+++ b/mllib/src/main/scala/org/apache/spark/ml/regression/IsotonicRegression.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.ml.regression
 
 import org.apache.spark.Logging
-import org.apache.spark.annotation.Experimental
+import org.apache.spark.annotation.{Experimental, Since}
 import org.apache.spark.ml.{Estimator, Model}
 import org.apache.spark.ml.param._
 import org.apache.spark.ml.param.shared.{HasFeaturesCol, HasLabelCol, HasPredictionCol, HasWeightCol}
@@ -124,32 +124,42 @@ private[regression] trait IsotonicRegressionBase extends Params with HasFeatures
  *
  * Uses [[org.apache.spark.mllib.regression.IsotonicRegression]].
  */
+@Since("1.5.0")
 @Experimental
-class IsotonicRegression(override val uid: String) extends Estimator[IsotonicRegressionModel]
-  with IsotonicRegressionBase {
+class IsotonicRegression @Since("1.5.0") (@Since("1.5.0") override val uid: String)
+  extends Estimator[IsotonicRegressionModel] with IsotonicRegressionBase {
 
+  @Since("1.5.0")
   def this() = this(Identifiable.randomUID("isoReg"))
 
   /** @group setParam */
+  @Since("1.5.0")
   def setLabelCol(value: String): this.type = set(labelCol, value)
 
   /** @group setParam */
+  @Since("1.5.0")
   def setFeaturesCol(value: String): this.type = set(featuresCol, value)
 
   /** @group setParam */
+  @Since("1.5.0")
   def setPredictionCol(value: String): this.type = set(predictionCol, value)
 
   /** @group setParam */
+  @Since("1.5.0")
   def setIsotonic(value: Boolean): this.type = set(isotonic, value)
 
   /** @group setParam */
+  @Since("1.5.0")
   def setWeightCol(value: String): this.type = set(weightCol, value)
 
   /** @group setParam */
+  @Since("1.5.0")
   def setFeatureIndex(value: Int): this.type = set(featureIndex, value)
 
+  @Since("1.5.0")
   override def copy(extra: ParamMap): IsotonicRegression = defaultCopy(extra)
 
+  @Since("1.5.0")
   override def fit(dataset: DataFrame): IsotonicRegressionModel = {
     validateAndTransformSchema(dataset.schema, fitting = true)
     // Extract columns from data.  If dataset is persisted, do not persist oldDataset.
@@ -163,6 +173,7 @@ class IsotonicRegression(override val uid: String) extends Estimator[IsotonicReg
     copyValues(new IsotonicRegressionModel(uid, oldModel).setParent(this))
   }
 
+  @Since("1.5.0")
   override def transformSchema(schema: StructType): StructType = {
     validateAndTransformSchema(schema, fitting = true)
   }
@@ -178,6 +189,7 @@ class IsotonicRegression(override val uid: String) extends Estimator[IsotonicReg
  * @param oldModel A [[org.apache.spark.mllib.regression.IsotonicRegressionModel]]
  *                 model trained by [[org.apache.spark.mllib.regression.IsotonicRegression]].
  */
+@Since("1.5.0")
 @Experimental
 class IsotonicRegressionModel private[ml] (
     override val uid: String,
@@ -185,27 +197,34 @@ class IsotonicRegressionModel private[ml] (
   extends Model[IsotonicRegressionModel] with IsotonicRegressionBase {
 
   /** @group setParam */
+  @Since("1.5.0")
   def setFeaturesCol(value: String): this.type = set(featuresCol, value)
 
   /** @group setParam */
+  @Since("1.5.0")
   def setPredictionCol(value: String): this.type = set(predictionCol, value)
 
   /** @group setParam */
+  @Since("1.5.0")
   def setFeatureIndex(value: Int): this.type = set(featureIndex, value)
 
   /** Boundaries in increasing order for which predictions are known. */
+  @Since("1.5.0")
   def boundaries: Vector = Vectors.dense(oldModel.boundaries)
 
   /**
    * Predictions associated with the boundaries at the same index, monotone because of isotonic
    * regression.
    */
+  @Since("1.5.0")
   def predictions: Vector = Vectors.dense(oldModel.predictions)
 
+  @Since("1.5.0")
   override def copy(extra: ParamMap): IsotonicRegressionModel = {
     copyValues(new IsotonicRegressionModel(uid, oldModel), extra).setParent(parent)
   }
 
+  @Since("1.5.0")
   override def transform(dataset: DataFrame): DataFrame = {
     val predict = dataset.schema($(featuresCol)).dataType match {
       case DoubleType =>
@@ -217,6 +236,7 @@ class IsotonicRegressionModel private[ml] (
     dataset.withColumn($(predictionCol), predict(col($(featuresCol))))
   }
 
+  @Since("1.5.0")
   override def transformSchema(schema: StructType): StructType = {
     validateAndTransformSchema(schema, fitting = false)
   }
diff --git a/mllib/src/main/scala/org/apache/spark/ml/regression/LinearRegression.scala b/mllib/src/main/scala/org/apache/spark/ml/regression/LinearRegression.scala
index 6638313818..913140e581 100644
--- a/mllib/src/main/scala/org/apache/spark/ml/regression/LinearRegression.scala
+++ b/mllib/src/main/scala/org/apache/spark/ml/regression/LinearRegression.scala
@@ -24,9 +24,9 @@ import breeze.optimize.{CachedDiffFunction, DiffFunction, LBFGS => BreezeLBFGS,
 import breeze.stats.distributions.StudentsT
 
 import org.apache.spark.{Logging, SparkException}
-import org.apache.spark.annotation.Experimental
 import org.apache.spark.ml.feature.Instance
 import org.apache.spark.ml.optim.WeightedLeastSquares
+import org.apache.spark.annotation.{Experimental, Since}
 import org.apache.spark.ml.PredictorParams
 import org.apache.spark.ml.param.ParamMap
 import org.apache.spark.ml.param.shared._
@@ -61,11 +61,13 @@ private[regression] trait LinearRegressionParams extends PredictorParams
  *  - L1 (Lasso)
  *  - L2 + L1 (elastic net)
  */
+@Since("1.3.0")
 @Experimental
-class LinearRegression(override val uid: String)
+class LinearRegression @Since("1.3.0") (@Since("1.3.0") override val uid: String)
   extends Regressor[Vector, LinearRegression, LinearRegressionModel]
   with LinearRegressionParams with Logging {
 
+  @Since("1.4.0")
   def this() = this(Identifiable.randomUID("linReg"))
 
   /**
@@ -73,6 +75,7 @@ class LinearRegression(override val uid: String)
    * Default is 0.0.
    * @group setParam
    */
+  @Since("1.3.0")
   def setRegParam(value: Double): this.type = set(regParam, value)
   setDefault(regParam -> 0.0)
 
@@ -81,6 +84,7 @@ class LinearRegression(override val uid: String)
    * Default is true.
    * @group setParam
    */
+  @Since("1.5.0")
   def setFitIntercept(value: Boolean): this.type = set(fitIntercept, value)
   setDefault(fitIntercept -> true)
 
@@ -93,6 +97,7 @@ class LinearRegression(override val uid: String)
    * Default is true.
    * @group setParam
    */
+  @Since("1.5.0")
   def setStandardization(value: Boolean): this.type = set(standardization, value)
   setDefault(standardization -> true)
 
@@ -103,6 +108,7 @@ class LinearRegression(override val uid: String)
    * Default is 0.0 which is an L2 penalty.
    * @group setParam
    */
+  @Since("1.4.0")
   def setElasticNetParam(value: Double): this.type = set(elasticNetParam, value)
   setDefault(elasticNetParam -> 0.0)
 
@@ -111,6 +117,7 @@ class LinearRegression(override val uid: String)
    * Default is 100.
    * @group setParam
    */
+  @Since("1.3.0")
   def setMaxIter(value: Int): this.type = set(maxIter, value)
   setDefault(maxIter -> 100)
 
@@ -120,6 +127,7 @@ class LinearRegression(override val uid: String)
    * Default is 1E-6.
    * @group setParam
    */
+  @Since("1.4.0")
   def setTol(value: Double): this.type = set(tol, value)
   setDefault(tol -> 1E-6)
 
@@ -129,6 +137,7 @@ class LinearRegression(override val uid: String)
    * Default is empty, so all instances have weight one.
    * @group setParam
    */
+  @Since("1.6.0")
   def setWeightCol(value: String): this.type = set(weightCol, value)
   setDefault(weightCol -> "")
 
@@ -139,6 +148,7 @@ class LinearRegression(override val uid: String)
    * selected automatically.
    * @group setParam
    */
+  @Since("1.6.0")
   def setSolver(value: String): this.type = set(solver, value)
   setDefault(solver -> "auto")
 
@@ -329,6 +339,7 @@ class LinearRegression(override val uid: String)
     model.setSummary(trainingSummary)
   }
 
+  @Since("1.4.0")
   override def copy(extra: ParamMap): LinearRegression = defaultCopy(extra)
 }
 
@@ -336,6 +347,7 @@ class LinearRegression(override val uid: String)
  * :: Experimental ::
  * Model produced by [[LinearRegression]].
  */
+@Since("1.3.0")
 @Experimental
 class LinearRegressionModel private[ml] (
     override val uid: String,
@@ -355,6 +367,7 @@ class LinearRegressionModel private[ml] (
    * Gets summary (e.g. residuals, mse, r-squared ) of model on training set. An exception is
    * thrown if `trainingSummary == None`.
    */
+  @Since("1.5.0")
   def summary: LinearRegressionTrainingSummary = trainingSummary match {
     case Some(summ) => summ
     case None =>
@@ -369,6 +382,7 @@ class LinearRegressionModel private[ml] (
   }
 
   /** Indicates whether a training summary exists for this model instance. */
+  @Since("1.5.0")
   def hasSummary: Boolean = trainingSummary.isDefined
 
   /**
@@ -402,6 +416,7 @@ class LinearRegressionModel private[ml] (
     dot(features, coefficients) + intercept
   }
 
+  @Since("1.4.0")
   override def copy(extra: ParamMap): LinearRegressionModel = {
     val newModel = copyValues(new LinearRegressionModel(uid, coefficients, intercept), extra)
     if (trainingSummary.isDefined) newModel.setSummary(trainingSummary.get)
@@ -416,6 +431,7 @@ class LinearRegressionModel private[ml] (
  * @param predictions predictions outputted by the model's `transform` method.
  * @param objectiveHistory objective function (scaled loss + regularization) at each iteration.
  */
+@Since("1.5.0")
 @Experimental
 class LinearRegressionTrainingSummary private[regression] (
     predictions: DataFrame,
@@ -428,6 +444,7 @@ class LinearRegressionTrainingSummary private[regression] (
   extends LinearRegressionSummary(predictions, predictionCol, labelCol, model, diagInvAtWA) {
 
   /** Number of training iterations until termination */
+  @Since("1.5.0")
   val totalIterations = objectiveHistory.length
 
 }
@@ -437,6 +454,7 @@ class LinearRegressionTrainingSummary private[regression] (
  * Linear regression results evaluated on a dataset.
  * @param predictions predictions outputted by the model's `transform` method.
  */
+@Since("1.5.0")
 @Experimental
 class LinearRegressionSummary private[regression] (
     @transient val predictions: DataFrame,
@@ -455,33 +473,39 @@ class LinearRegressionSummary private[regression] (
    * explainedVariance = 1 - variance(y - \hat{y}) / variance(y)
    * Reference: [[http://en.wikipedia.org/wiki/Explained_variation]]
    */
+  @Since("1.5.0")
   val explainedVariance: Double = metrics.explainedVariance
 
   /**
    * Returns the mean absolute error, which is a risk function corresponding to the
    * expected value of the absolute error loss or l1-norm loss.
    */
+  @Since("1.5.0")
   val meanAbsoluteError: Double = metrics.meanAbsoluteError
 
   /**
    * Returns the mean squared error, which is a risk function corresponding to the
    * expected value of the squared error loss or quadratic loss.
    */
+  @Since("1.5.0")
   val meanSquaredError: Double = metrics.meanSquaredError
 
   /**
    * Returns the root mean squared error, which is defined as the square root of
    * the mean squared error.
    */
+  @Since("1.5.0")
   val rootMeanSquaredError: Double = metrics.rootMeanSquaredError
 
   /**
    * Returns R^2^, the coefficient of determination.
    * Reference: [[http://en.wikipedia.org/wiki/Coefficient_of_determination]]
    */
+  @Since("1.5.0")
   val r2: Double = metrics.r2
 
   /** Residuals (label - predicted value) */
+  @Since("1.5.0")
   @transient lazy val residuals: DataFrame = {
     val t = udf { (pred: Double, label: Double) => label - pred }
     predictions.select(t(col(predictionCol), col(labelCol)).as("residuals"))
diff --git a/mllib/src/main/scala/org/apache/spark/ml/regression/RandomForestRegressor.scala b/mllib/src/main/scala/org/apache/spark/ml/regression/RandomForestRegressor.scala
index 64fc17247c..71e40b513e 100644
--- a/mllib/src/main/scala/org/apache/spark/ml/regression/RandomForestRegressor.scala
+++ b/mllib/src/main/scala/org/apache/spark/ml/regression/RandomForestRegressor.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.ml.regression
 
-import org.apache.spark.annotation.Experimental
+import org.apache.spark.annotation.{Experimental, Since}
 import org.apache.spark.ml.{PredictionModel, Predictor}
 import org.apache.spark.ml.param.ParamMap
 import org.apache.spark.ml.tree.{DecisionTreeModel, RandomForestParams, TreeEnsembleModel, TreeRegressorParams}
@@ -37,44 +37,55 @@ import org.apache.spark.sql.functions._
  * [[http://en.wikipedia.org/wiki/Random_forest  Random Forest]] learning algorithm for regression.
  * It supports both continuous and categorical features.
  */
+@Since("1.4.0")
 @Experimental
-final class RandomForestRegressor(override val uid: String)
+final class RandomForestRegressor @Since("1.4.0") (@Since("1.4.0") override val uid: String)
   extends Predictor[Vector, RandomForestRegressor, RandomForestRegressionModel]
   with RandomForestParams with TreeRegressorParams {
 
+  @Since("1.4.0")
   def this() = this(Identifiable.randomUID("rfr"))
 
   // Override parameter setters from parent trait for Java API compatibility.
 
   // Parameters from TreeRegressorParams:
-
+  @Since("1.4.0")
   override def setMaxDepth(value: Int): this.type = super.setMaxDepth(value)
 
+  @Since("1.4.0")
   override def setMaxBins(value: Int): this.type = super.setMaxBins(value)
 
+  @Since("1.4.0")
   override def setMinInstancesPerNode(value: Int): this.type =
     super.setMinInstancesPerNode(value)
 
+  @Since("1.4.0")
   override def setMinInfoGain(value: Double): this.type = super.setMinInfoGain(value)
 
+  @Since("1.4.0")
   override def setMaxMemoryInMB(value: Int): this.type = super.setMaxMemoryInMB(value)
 
+  @Since("1.4.0")
   override def setCacheNodeIds(value: Boolean): this.type = super.setCacheNodeIds(value)
 
+  @Since("1.4.0")
   override def setCheckpointInterval(value: Int): this.type = super.setCheckpointInterval(value)
 
+  @Since("1.4.0")
   override def setImpurity(value: String): this.type = super.setImpurity(value)
 
   // Parameters from TreeEnsembleParams:
-
+  @Since("1.4.0")
   override def setSubsamplingRate(value: Double): this.type = super.setSubsamplingRate(value)
 
+  @Since("1.4.0")
   override def setSeed(value: Long): this.type = super.setSeed(value)
 
   // Parameters from RandomForestParams:
-
+  @Since("1.4.0")
   override def setNumTrees(value: Int): this.type = super.setNumTrees(value)
 
+  @Since("1.4.0")
   override def setFeatureSubsetStrategy(value: String): this.type =
     super.setFeatureSubsetStrategy(value)
 
@@ -91,15 +102,19 @@ final class RandomForestRegressor(override val uid: String)
     new RandomForestRegressionModel(trees, numFeatures)
   }
 
+  @Since("1.4.0")
   override def copy(extra: ParamMap): RandomForestRegressor = defaultCopy(extra)
 }
 
+@Since("1.4.0")
 @Experimental
 object RandomForestRegressor {
   /** Accessor for supported impurity settings: variance */
+  @Since("1.4.0")
   final val supportedImpurities: Array[String] = TreeRegressorParams.supportedImpurities
 
   /** Accessor for supported featureSubsetStrategy settings: auto, all, onethird, sqrt, log2 */
+  @Since("1.4.0")
   final val supportedFeatureSubsetStrategies: Array[String] =
     RandomForestParams.supportedFeatureSubsetStrategies
 }
@@ -111,6 +126,7 @@ object RandomForestRegressor {
  * @param _trees  Decision trees in the ensemble.
  * @param numFeatures  Number of features used by this model
  */
+@Since("1.4.0")
 @Experimental
 final class RandomForestRegressionModel private[ml] (
     override val uid: String,
@@ -128,11 +144,13 @@ final class RandomForestRegressionModel private[ml] (
   private[ml] def this(trees: Array[DecisionTreeRegressionModel], numFeatures: Int) =
     this(Identifiable.randomUID("rfr"), trees, numFeatures)
 
+  @Since("1.4.0")
   override def trees: Array[DecisionTreeModel] = _trees.asInstanceOf[Array[DecisionTreeModel]]
 
   // Note: We may add support for weights (based on tree performance) later on.
   private lazy val _treeWeights: Array[Double] = Array.fill[Double](numTrees)(1.0)
 
+  @Since("1.4.0")
   override def treeWeights: Array[Double] = _treeWeights
 
   override protected def transformImpl(dataset: DataFrame): DataFrame = {
@@ -150,10 +168,12 @@ final class RandomForestRegressionModel private[ml] (
     _trees.map(_.rootNode.predictImpl(features).prediction).sum / numTrees
   }
 
+  @Since("1.4.0")
   override def copy(extra: ParamMap): RandomForestRegressionModel = {
     copyValues(new RandomForestRegressionModel(uid, _trees, numFeatures), extra).setParent(parent)
   }
 
+  @Since("1.4.0")
   override def toString: String = {
     s"RandomForestRegressionModel (uid=$uid) with $numTrees trees"
   }