Github user felixcheung commented on a diff in the pull request:
https://github.com/apache/spark/pull/17728#discussion_r112822261
--- Diff: R/pkg/R/DataFrame.R ---
@@ -3642,3 +3642,58 @@ setMethod("checkpoint",
df <- callJMethod(x@sdf, "checkpoint", as.logical(eager))
dataFrame(df)
})
+
+
+#' cube
+#'
+#' Create a multi-dimensional cube for the SparkDataFrame using the
specified columns.
+#'
+#' @param x a SparkDataFrame.
+#' @param ... variable(s) (character names(s) or Column(s)) to group on.
+#' @return A GroupedData.
+#' @family SparkDataFrame functions
+#' @aliases cube,SparkDataFrame-method
+#' @rdname cube
+#' @name cube
+#' @export
+#' @examples
+#' \dontrun{
+#' df <- createDataFrame(mtcars)
+#' mean(cube(df, "cyl", "gear", "am"), "mpg")
+#' }
+#' @note cube since 2.3.0
+setMethod("cube",
+ signature(x = "SparkDataFrame"),
+ function(x, ...) {
+ cols <- list(...)
+ jcol <- lapply(cols, function(x) if (is.character(x))
column(x)@jc else x@jc)
--- End diff --
nit: I'd flip this since Column is a stronger type, and also this way there
is a nicer error message
instead of `if (is.character(x)) column(x)@jc else x@jc`
do `if (class(x) == "Column") x@jc else column(x)@jc`
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