Merge branch 'dputler-master'

Author: shivaram

pkg/R/context.R

@@ -85,11 +85,17 @@ parallelize <- function(sc, coll, numSlices = 1) {
   # TODO: bound/safeguard numSlices
   # TODO: unit tests for if the split works for all primitives
   # TODO: support matrix, data frame, etc
-  if (!is.list(coll)) {
-    if (!is.vector(coll)) {
-      message(paste("context.R: parallelize() currently only supports lists and vectors.",
-                    "Calling as.list() to coerce coll into a list."))
-    }
+	if ((!is.list(coll) && !is.vector(coll)) || is.data.frame(coll)) {
+		if (is.data.frame(coll)) {
+			message(paste("context.R: A data frame is parallelized by columns."))
+		} else {
+			if (is.matrix(coll)) {
+				message(paste("context.R: A matrix is parallelized by elements."))
+    		} else {
+      			message(paste("context.R: parallelize() currently only supports lists and vectors.",
+							            "Calling as.list() to coerce coll into a list."))
+        }
+		}
     coll <- as.list(coll)
   }
 
@@ -109,7 +115,6 @@ parallelize <- function(sc, coll, numSlices = 1) {
   RDD(jrdd, TRUE)
 }
 
-
 #' Include this specified package on all workers
 #'
 #' This function can be used to include a package on all workers before the