[SPARK-9609] [MLLIB] Fix spelling of Strategy.defaultStrategy

jkbradley

Author: Feynman Liang <fliang@databricks.com>

Closes #7941 from feynmanliang/SPARK-9609-stategy-spelling and squashes the following commits:

d2aafb1 [Feynman Liang] Add deprecated backwards compatibility
aa090a8 [Feynman Liang] Fix spelling

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

@@ -163,7 +163,7 @@ private[ml] trait DecisionTreeParams extends PredictorParams {
       oldAlgo: OldAlgo.Algo,
       oldImpurity: OldImpurity,
       subsamplingRate: Double): OldStrategy = {
-    val strategy = OldStrategy.defaultStategy(oldAlgo)
+    val strategy = OldStrategy.defaultStrategy(oldAlgo)
     strategy.impurity = oldImpurity
     strategy.checkpointInterval = getCheckpointInterval
     strategy.maxBins = getMaxBins

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

@@ -90,7 +90,7 @@ object BoostingStrategy {
    * @return Configuration for boosting algorithm
    */
   def defaultParams(algo: Algo): BoostingStrategy = {
-    val treeStrategy = Strategy.defaultStategy(algo)
+    val treeStrategy = Strategy.defaultStrategy(algo)
     treeStrategy.maxDepth = 3
     algo match {
       case Algo.Classification =>

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

@@ -178,14 +178,14 @@ object Strategy {
    * @param algo  "Classification" or "Regression"
    */
   def defaultStrategy(algo: String): Strategy = {
-    defaultStategy(Algo.fromString(algo))
+    defaultStrategy(Algo.fromString(algo))
   }
 
   /**
    * Construct a default set of parameters for [[org.apache.spark.mllib.tree.DecisionTree]]
    * @param algo Algo.Classification or Algo.Regression
    */
-  def defaultStategy(algo: Algo): Strategy = algo match {
+  def defaultStrategy(algo: Algo): Strategy = algo match {
     case Algo.Classification =>
       new Strategy(algo = Classification, impurity = Gini, maxDepth = 10,
         numClasses = 2)
@@ -193,4 +193,8 @@ object Strategy {
       new Strategy(algo = Regression, impurity = Variance, maxDepth = 10,
         numClasses = 0)
   }
+
+  @deprecated("Use Strategy.defaultStrategy instead.", "1.5.0")
+  def defaultStategy(algo: Algo): Strategy = defaultStrategy(algo)
+
 }