From 73c53a5a49ffbcce8e25d0fc3be09dba50949ede Mon Sep 17 00:00:00 2001
From: Felix Cheung <felixcheung_m@hotmail.com>
Date: Thu, 1 Sep 2016 23:09:56 -0700
Subject: [PATCH] update doc

---
 R/pkg/R/functions.R | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/R/pkg/R/functions.R b/R/pkg/R/functions.R
index dbf8dd89a204..369b1d00d9e5 100644
--- a/R/pkg/R/functions.R
+++ b/R/pkg/R/functions.R
@@ -2876,7 +2876,8 @@ setMethod("randn", signature(seed = "numeric"),
 
 #' regexp_extract
 #'
-#' Extract a specific(idx) group identified by a java regex, from the specified string column.
+#' Extract a specific \code{idx} group identified by a Java regex, from the specified string column.
+#' If the regex did not match, or the specified group did not match, an empty string is returned.
 #'
 #' @param x a string Column.
 #' @param pattern a regular expression.