From 8a556c068e65c7d59a840e76fb33890b3f688f96 Mon Sep 17 00:00:00 2001
From: hadley <h.wickham@gmail.com>
Date: Thu, 20 Nov 2014 13:11:53 -0600
Subject: [PATCH] Implement add_rownames()

Closes #639
---
 NAMESPACE           |  1 +
 R/dataframe.R       | 19 +++++++++++++++++++
 man/add_rownames.Rd | 22 ++++++++++++++++++++++
 3 files changed, 42 insertions(+)
 create mode 100644 man/add_rownames.Rd

diff --git a/NAMESPACE b/NAMESPACE
index 20bdab255f..399c9a6fdd 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -289,6 +289,7 @@ S3method(update,tbl_sql)
 export("%.%")
 export("%>%")
 export(.datatable.aware)
+export(add_rownames)
 export(anti_join)
 export(arrange)
 export(arrange_)
diff --git a/R/dataframe.R b/R/dataframe.R
index b7808aa722..ee2530ad74 100644
--- a/R/dataframe.R
+++ b/R/dataframe.R
@@ -130,3 +130,22 @@ as_data_frame <- function(x) {
 
   x
 }
+
+#' Convert row names to an explicit variable.
+#'
+#' @param df Input data frame with rownames.
+#' @param var Name of variable to use
+#' @export
+#' @examples
+#' mtcars %>%
+#'   tbl_df() %>%
+#'   print() %>%
+#'   add_rownames()
+add_rownames <- function(df, var = "rowname") {
+  stopifnot(is.data.frame(df))
+
+  df[[var]] <- rownames(df)
+  rownames(df) <- NULL
+
+  df
+}
diff --git a/man/add_rownames.Rd b/man/add_rownames.Rd
new file mode 100644
index 0000000000..aec5a90623
--- /dev/null
+++ b/man/add_rownames.Rd
@@ -0,0 +1,22 @@
+% Generated by roxygen2 (4.0.2): do not edit by hand
+\name{add_rownames}
+\alias{add_rownames}
+\title{Convert row names to an explicit variable.}
+\usage{
+add_rownames(df, var = "rowname")
+}
+\arguments{
+\item{df}{Input data frame with rownames.}
+
+\item{var}{Name of variable to use}
+}
+\description{
+Convert row names to an explicit variable.
+}
+\examples{
+mtcars \%>\%
+  tbl_df() \%>\%
+  print() \%>\%
+  add_rownames()
+}
+