[SPARK-15159][SPARKR] SparkSession roxygen2 doc, programming guide, example updates

## What changes were proposed in this pull request?

roxygen2 doc, programming guide, example updates

## How was this patch tested?

manual checks
shivaram

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #13751 from felixcheung/rsparksessiondoc.

5 files changed, 92 insertions, 161 deletions

diff --git a/R/pkg/R/DataFrame.R b/R/pkg/R/DataFrame.R
index f3a3eff46d..583d3aefd4 100644
--- a/R/pkg/R/DataFrame.R
+++ b/R/pkg/R/DataFrame.R
@@ -35,12 +35,11 @@ setOldClass("structType")
 #' @slot env An R environment that stores bookkeeping states of the SparkDataFrame
 #' @slot sdf A Java object reference to the backing Scala DataFrame
 #' @seealso \link{createDataFrame}, \link{read.json}, \link{table}
-#' @seealso \url{https://spark.apache.org/docs/latest/sparkr.html#sparkr-dataframes}
+#' @seealso \url{https://spark.apache.org/docs/latest/sparkr.html#sparkdataframe}
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df <- createDataFrame(faithful)
 #'}
 setClass("SparkDataFrame",
@@ -77,8 +76,7 @@ dataFrame <- function(sdf, isCached = FALSE) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' printSchema(df)
@@ -102,8 +100,7 @@ setMethod("printSchema",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' dfSchema <- schema(df)
@@ -126,8 +123,7 @@ setMethod("schema",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' explain(df, TRUE)
@@ -157,8 +153,7 @@ setMethod("explain",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' isLocal(df)
@@ -182,8 +177,7 @@ setMethod("isLocal",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' showDF(df)
@@ -207,8 +201,7 @@ setMethod("showDF",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' df
@@ -234,8 +227,7 @@ setMethod("show", "SparkDataFrame",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' dtypes(df)
@@ -261,8 +253,7 @@ setMethod("dtypes",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' columns(df)
@@ -396,8 +387,7 @@ setMethod("coltypes",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' coltypes(df) <- c("character", "integer")
@@ -432,7 +422,7 @@ setMethod("coltypes<-",
 
 #' Creates a temporary view using the given name.
 #'
-#' Creates a new temporary view using a SparkDataFrame in the SQLContext. If a
+#' Creates a new temporary view using a SparkDataFrame in the Spark Session. If a
 #' temporary view with the same name already exists, replaces it.
 #'
 #' @param x A SparkDataFrame
@@ -444,8 +434,7 @@ setMethod("coltypes<-",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' createOrReplaceTempView(df, "json_df")
@@ -469,8 +458,7 @@ setMethod("createOrReplaceTempView",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' registerTempTable(df, "json_df")
@@ -498,8 +486,7 @@ setMethod("registerTempTable",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df <- read.df(path, "parquet")
 #' df2 <- read.df(path2, "parquet")
 #' createOrReplaceTempView(df, "table1")
@@ -526,8 +513,7 @@ setMethod("insertInto",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' cache(df)
@@ -554,8 +540,7 @@ setMethod("cache",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' persist(df, "MEMORY_AND_DISK")
@@ -582,8 +567,7 @@ setMethod("persist",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' persist(df, "MEMORY_AND_DISK")
@@ -617,8 +601,7 @@ setMethod("unpersist",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' newDF <- repartition(df, 2L)
@@ -660,8 +643,7 @@ setMethod("repartition",
 #' @noRd
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' newRDD <- toJSON(df)
@@ -688,8 +670,7 @@ setMethod("toJSON",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' write.json(df, "/tmp/sparkr-tmp/")
@@ -742,8 +723,7 @@ setMethod("write.orc",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' write.parquet(df, "/tmp/sparkr-tmp1/")
@@ -781,8 +761,7 @@ setMethod("saveAsParquetFile",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.txt"
 #' df <- read.text(path)
 #' write.text(df, "/tmp/sparkr-tmp/")
@@ -806,8 +785,7 @@ setMethod("write.text",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' distinctDF <- distinct(df)
@@ -842,8 +820,7 @@ setMethod("unique",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' collect(sample(df, FALSE, 0.5))
@@ -883,8 +860,7 @@ setMethod("sample_frac",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' count(df)
@@ -913,8 +889,7 @@ setMethod("nrow",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' ncol(df)
@@ -936,8 +911,7 @@ setMethod("ncol",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' dim(df)
@@ -960,8 +934,7 @@ setMethod("dim",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' collected <- collect(df)
@@ -1032,8 +1005,7 @@ setMethod("collect",
 #' @export
 #' @examples
 #' \dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' limitedDF <- limit(df, 10)
@@ -1053,8 +1025,7 @@ setMethod("limit",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' take(df, 2)
@@ -1082,8 +1053,7 @@ setMethod("take",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' head(df)
@@ -1105,8 +1075,7 @@ setMethod("head",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' first(df)
@@ -1126,8 +1095,7 @@ setMethod("first",
 #' @noRd
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' rdd <- toRDD(df)
@@ -1662,8 +1630,7 @@ setMethod("select",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' selectExpr(df, "col1", "(col2 * 5) as newCol")
@@ -1692,8 +1659,7 @@ setMethod("selectExpr",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' newDF <- withColumn(df, "newCol", df$col1 * 5)
@@ -1721,8 +1687,7 @@ setMethod("withColumn",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' newDF <- mutate(df, newCol = df$col1 * 5, newCol2 = df$col1 * 2)
@@ -1812,8 +1777,7 @@ setMethod("transform",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' newDF <- withColumnRenamed(df, "col1", "newCol1")
@@ -1837,8 +1801,7 @@ setMethod("withColumnRenamed",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' newDF <- rename(df, col1 = df$newCol1)
@@ -1881,8 +1844,7 @@ setClassUnion("characterOrColumn", c("character", "Column"))
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' arrange(df, df$col1)
@@ -1957,8 +1919,7 @@ setMethod("orderBy",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' filter(df, "col1 > 0")
@@ -1998,8 +1959,7 @@ setMethod("where",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' dropDuplicates(df)
@@ -2045,8 +2005,7 @@ setMethod("dropDuplicates",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df1 <- read.json(path)
 #' df2 <- read.json(path2)
 #' join(df1, df2) # Performs a Cartesian
@@ -2103,8 +2062,7 @@ setMethod("join",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df1 <- read.json(path)
 #' df2 <- read.json(path2)
 #' merge(df1, df2) # Performs a Cartesian
@@ -2235,8 +2193,7 @@ generateAliasesForIntersectedCols <- function (x, intersectedColNames, suffix) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df1 <- read.json(path)
 #' df2 <- read.json(path2)
 #' unioned <- unionAll(df, df2)
@@ -2279,8 +2236,7 @@ setMethod("rbind",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df1 <- read.json(path)
 #' df2 <- read.json(path2)
 #' intersectDF <- intersect(df, df2)
@@ -2306,8 +2262,7 @@ setMethod("intersect",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df1 <- read.json(path)
 #' df2 <- read.json(path2)
 #' exceptDF <- except(df, df2)
@@ -2349,8 +2304,7 @@ setMethod("except",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' write.df(df, "myfile", "parquet", "overwrite")
@@ -2408,8 +2362,7 @@ setMethod("saveDF",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' saveAsTable(df, "myfile")
@@ -2445,8 +2398,7 @@ setMethod("saveAsTable",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' describe(df)
@@ -2501,10 +2453,9 @@ setMethod("summary",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlCtx <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
-#' df <- read.json(sqlCtx, path)
+#' df <- read.json(path)
 #' dropna(df)
 #' }
 setMethod("dropna",
@@ -2555,10 +2506,9 @@ setMethod("na.omit",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlCtx <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
-#' df <- read.json(sqlCtx, path)
+#' df <- read.json(path)
 #' fillna(df, 1)
 #' fillna(df, list("age" = 20, "name" = "unknown"))
 #' }
@@ -2769,10 +2719,9 @@ setMethod("str",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlCtx <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
-#' df <- read.json(sqlCtx, path)
+#' df <- read.json(path)
 #' drop(df, "col1")
 #' drop(df, c("col1", "col2"))
 #' drop(df, df$col1)
@@ -2943,8 +2892,7 @@ setMethod("histogram",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' jdbcUrl <- "jdbc:mysql://localhost:3306/databasename"
 #' write.jdbc(df, jdbcUrl, "table", user = "username", password = "password")
 #' }
@@ -2972,8 +2920,7 @@ setMethod("write.jdbc",
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df <- createDataFrame(data.frame(id = 1:1000))
 #' df_list <- randomSplit(df, c(2, 3, 5), 0)
 #' # df_list contains 3 SparkDataFrames with each having about 200, 300 and 500 rows respectively
diff --git a/R/pkg/R/SQLContext.R b/R/pkg/R/SQLContext.R
index b7e1c062c7..b846b3dec2 100644
--- a/R/pkg/R/SQLContext.R
+++ b/R/pkg/R/SQLContext.R
@@ -126,8 +126,7 @@ getDefaultSqlSource <- function() {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df1 <- as.DataFrame(iris)
 #' df2 <- as.DataFrame(list(3,4,5,6))
 #' df3 <- createDataFrame(iris)
@@ -238,8 +237,7 @@ as.DataFrame <- function(x, ...) {
 #' @noRd
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' rdd <- lapply(parallelize(sc, 1:10), function(x) list(a=x, b=as.character(x)))
 #' df <- toDF(rdd)
 #'}
@@ -261,8 +259,7 @@ setMethod("toDF", signature(x = "RDD"),
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' df <- jsonFile(path)
@@ -309,8 +306,7 @@ jsonFile <- function(x, ...) {
 #' @noRd
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' rdd <- texFile(sc, "path/to/json")
 #' df <- jsonRDD(sqlContext, rdd)
 #'}
@@ -401,8 +397,7 @@ parquetFile <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.txt"
 #' df <- read.text(path)
 #' }
@@ -432,8 +427,7 @@ read.text <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' createOrReplaceTempView(df, "table")
@@ -464,8 +458,7 @@ sql <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' createOrReplaceTempView(df, "table")
@@ -489,8 +482,7 @@ tableToDF <- function(tableName) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' tables("hive")
 #' }
 #' @name tables
@@ -516,8 +508,7 @@ tables <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' tableNames("hive")
 #' }
 #' @name tableNames
@@ -545,8 +536,7 @@ tableNames <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' createOrReplaceTempView(df, "table")
@@ -575,8 +565,7 @@ cacheTable <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' path <- "path/to/file.json"
 #' df <- read.json(path)
 #' createOrReplaceTempView(df, "table")
@@ -629,8 +618,7 @@ clearCache <- function() {
 #' @export
 #' @examples
 #' \dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df <- read.df(path, "parquet")
 #' createOrReplaceTempView(df, "table")
 #' dropTempTable("table")
@@ -694,8 +682,7 @@ dropTempView <- function(viewName) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' df1 <- read.df("path/to/file.json", source = "json")
 #' schema <- structType(structField("name", "string"),
 #'                      structField("info", "map<string,double>"))
@@ -758,9 +745,8 @@ loadDF <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
-#' df <- sparkRSQL.createExternalTable("myjson", path="path/to/json", source="json")
+#' sparkR.session()
+#' df <- createExternalTable("myjson", path="path/to/json", source="json")
 #' }
 #' @name createExternalTable
 #' @method createExternalTable default
@@ -806,8 +792,7 @@ createExternalTable <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' jdbcUrl <- "jdbc:mysql://localhost:3306/databasename"
 #' df <- read.jdbc(jdbcUrl, "table", predicates = list("field<=123"), user = "username")
 #' df2 <- read.jdbc(jdbcUrl, "table2", partitionColumn = "index", lowerBound = 0,
diff --git a/R/pkg/R/mllib.R b/R/pkg/R/mllib.R
index ba2eee2fca..2127daee18 100644
--- a/R/pkg/R/mllib.R
+++ b/R/pkg/R/mllib.R
@@ -67,8 +67,7 @@ setClass("KMeansModel", representation(jobj = "jobj"))
 #' @export
 #' @examples
 #' \dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' data(iris)
 #' df <- createDataFrame(iris)
 #' model <- spark.glm(df, Sepal_Length ~ Sepal_Width, family="gaussian")
@@ -115,8 +114,7 @@ setMethod(
 #' @export
 #' @examples
 #' \dontrun{
-#' sc <- sparkR.init()
-#' sqlContext <- sparkRSQL.init(sc)
+#' sparkR.session()
 #' data(iris)
 #' df <- createDataFrame(iris)
 #' model <- glm(Sepal_Length ~ Sepal_Width, df, family="gaussian")
diff --git a/R/pkg/R/schema.R b/R/pkg/R/schema.R
index 039aa008b3..89a2cfac3c 100644
--- a/R/pkg/R/schema.R
+++ b/R/pkg/R/schema.R
@@ -29,11 +29,11 @@
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlCtx <- sparkRSQL.init(sc)
-#' rdd <- lapply(parallelize(sc, 1:10), function(x) { list(x, as.character(x)) })
-#' schema <- structType(structField("a", "integer"), structField("b", "string"))
-#' df <- createDataFrame(sqlCtx, rdd, schema)
+#' schema <-  structType(structField("a", "integer"), structField("c", "string"),
+#'                       structField("avg", "double"))
+#' df1 <- gapply(df, list("a", "c"),
+#'               function(key, x) { y <- data.frame(key, mean(x$b), stringsAsFactors = FALSE) },
+#'               schema)
 #' }
 structType <- function(x, ...) {
   UseMethod("structType", x)
@@ -90,13 +90,13 @@ print.structType <- function(x, ...) {
 #' @export
 #' @examples
 #'\dontrun{
-#' sc <- sparkR.init()
-#' sqlCtx <- sparkRSQL.init(sc)
-#' rdd <- lapply(parallelize(sc, 1:10), function(x) { list(x, as.character(x)) })
-#' field1 <- structField("a", "integer", TRUE)
-#' field2 <- structField("b", "string", TRUE)
-#' schema <- structType(field1, field2)
-#' df <- createDataFrame(sqlCtx, rdd, schema)
+#' field1 <- structField("a", "integer")
+#' field2 <- structField("c", "string")
+#' field3 <- structField("avg", "double")
+#' schema <-  structType(field1, field2, field3)
+#' df1 <- gapply(df, list("a", "c"),
+#'               function(key, x) { y <- data.frame(key, mean(x$b), stringsAsFactors = FALSE) },
+#'               schema)
 #' }
 
 structField <- function(x, ...) {
diff --git a/R/pkg/R/sparkR.R b/R/pkg/R/sparkR.R
index 0dfd7b7530..d05660ccf6 100644
--- a/R/pkg/R/sparkR.R
+++ b/R/pkg/R/sparkR.R
@@ -89,9 +89,7 @@ sparkR.session.stop <- function() {
 
 #' (Deprecated) Initialize a new Spark Context.
 #'
-#' This function initializes a new SparkContext. For details on how to initialize
-#' and use SparkR, refer to SparkR programming guide at
-#' \url{http://spark.apache.org/docs/latest/sparkr.html#starting-up-sparkcontext-sqlcontext}.
+#' This function initializes a new SparkContext.
 #'
 #' @param master The Spark master URL
 #' @param appName Application name to register with cluster manager
@@ -312,6 +310,9 @@ sparkRHive.init <- function(jsc = NULL) {
 #' Additional Spark properties can be set (...), and these named parameters take priority over
 #' over values in master, appName, named lists of sparkConfig.
 #'
+#' For details on how to initialize and use SparkR, refer to SparkR programming guide at
+#' \url{http://spark.apache.org/docs/latest/sparkr.html#starting-up-sparksession}.
+#'
 #' @param master The Spark master URL
 #' @param appName Application name to register with cluster manager
 #' @param sparkHome Spark Home directory