From 157703d21f06f4ec9756ab097853b8cd1906347c Mon Sep 17 00:00:00 2001
From: hadley <h.wickham@gmail.com>
Date: Fri, 8 Apr 2011 08:29:23 -0500
Subject: [PATCH] Remove row names from colwise

---
 R/helper-col-wise.r | 22 ++++++----------------
 man/colwise.Rd      | 15 +++++----------
 2 files changed, 11 insertions(+), 26 deletions(-)

diff --git a/R/helper-col-wise.r b/R/helper-col-wise.r
index 6f2fd726..a7235642 100644
--- a/R/helper-col-wise.r
+++ b/R/helper-col-wise.r
@@ -2,17 +2,12 @@
 #' Turn a function that operates on a vector into a function that operates
 #' column-wise on a data.frame.
 #'
-#' By default, the generated function preserves the rownames of the data.frame.
-#' To set the rownames differently, you can specify an argument \code{row.names}
-#' to the generated function.
-#' All other arguments for the generated function will be handed down
-#' into the vector function.
-#'
-#' \code{catcolwise} and \code{numcolwise} provide versions that only operate
-#' on discrete and numeric columns respectively.
+#' \code{catcolwise} and \code{numcolwise} provide version that only operate
+#' on discrete and numeric variables respectively.
 #' 
-#' @param .fun function operating on a vector
-#' @param .cols either a function that tests columns for inclusion, or a quoted object giving which columns to process
+#' @param .fun function
+#' @param .cols either a function that tests columns for inclusion, or a
+#'   quoted object giving which columns to process
 #' @aliases colwise catcolwise numcolwise
 #' @export colwise numcolwise catcolwise
 #' @examples
@@ -53,17 +48,12 @@ colwise <- function(.fun, .cols = true) {
     filter <- function(df) Filter(.cols, df)
   }
   
-  function(df, row.names = NULL, ...) {
+  function(df, ...) {
     stopifnot(is.data.frame(df))
-    if (is.null(row.names)) row.names <- rownames(df)
-
     filtered <- filter(df)
     if (ncol(filtered) == 0) return(data.frame())
     
     df <- quickdf(lapply(filtered, .fun, ...))
-    if (nrow(df) == length(row.names)) {
-      rownames(df) <- row.names
-    }
     names(df) <- names(filtered)
     df
   }
diff --git a/man/colwise.Rd b/man/colwise.Rd
index 94ee22cf..271c986f 100644
--- a/man/colwise.Rd
+++ b/man/colwise.Rd
@@ -9,22 +9,17 @@
 }
 
 \details{
-  By default, the generated function preserves the rownames
-  of the data.frame. To set the rownames differently, you
-  can specify an argument \code{row.names} to the generated
-  function. All other arguments for the generated function
-  will be handed down into the vector function.
-
-  \code{catcolwise} and \code{numcolwise} provide versions
-  that only operate on discrete and numeric columns
+  \code{catcolwise} and \code{numcolwise} provide version
+  that only operate on discrete and numeric variables
   respectively.
 }
 \alias{colwise}
 \alias{catcolwise}
 \alias{numcolwise}
 \arguments{
-  \item{.fun}{function operating on a vector}
-  \item{.cols}{either a function that tests columns for inclusion, or a quoted object giving which columns to process}
+  \item{.fun}{function}
+  \item{.cols}{either a function that tests columns for inclusion, or a
+quoted object giving which columns to process}
 }
 \examples{# Count number of missing values
 nmissing <- function(x) sum(is.na(x))