[SPARK-19282] update the documentation on model summary

Author: keypointt

R/pkg/R/mllib_tree.R

@@ -200,8 +200,8 @@ setMethod("spark.gbt", signature(data = "SparkDataFrame", formula = "formula"),
 #' @return \code{summary} returns summary information of the fitted model, which is a list.
 #'         The list of components includes \code{formula} (formula),
 #'         \code{numFeatures} (number of features), \code{features} (list of features),
-#'         \code{featureImportances} (feature importances), \code{numTrees} (number of trees),
-#'         and \code{treeWeights} (tree weights).
+#'         \code{featureImportances} (feature importances), \code{maxDepth} (max depth of trees),
+#'         \code{numTrees} (number of trees), and \code{treeWeights} (tree weights).
 #' @rdname spark.gbt
 #' @aliases summary,GBTRegressionModel-method
 #' @export
@@ -406,8 +406,8 @@ setMethod("spark.randomForest", signature(data = "SparkDataFrame", formula = "fo
 #' @return \code{summary} returns summary information of the fitted model, which is a list.
 #'         The list of components includes \code{formula} (formula),
 #'         \code{numFeatures} (number of features), \code{features} (list of features),
-#'         \code{featureImportances} (feature importances), \code{numTrees} (number of trees),
-#'         and \code{treeWeights} (tree weights).
+#'         \code{featureImportances} (feature importances), \code{maxDepth} (max depth of trees),
+#'         \code{numTrees} (number of trees), and \code{treeWeights} (tree weights).
 #' @rdname spark.randomForest
 #' @aliases summary,RandomForestRegressionModel-method
 #' @export