added getThreshold to SVMModel

Author: jkbradley

mllib/src/main/scala/org/apache/spark/mllib/classification/SVM.scala

@@ -49,6 +49,13 @@ class SVMModel (
     this
   }
 
+  /**
+   * :: Experimental ::
+   * Returns the threshold (if any) used for converting raw prediction scores into 0/1 predictions.
+   */
+  @Experimental
+  def getThreshold: Option[Double] = threshold
+
   /**
    * :: Experimental ::
    * Clears the threshold so that `predict` will output raw prediction scores.