--- R-devel_2007-08-06/src/library/base/R/sweep.R	2007-07-27 17:51:13.000000000 +0200
+++ R-devel_2007-08-06-sweep/src/library/base/R/sweep.R	2007-08-07 10:30:12.383672960 +0200
@@ -14,10 +14,29 @@
 #  A copy of the GNU General Public License is available at
 #  http://www.r-project.org/Licenses/
 
-sweep <- function(x, MARGIN, STATS, FUN = "-", ...)
+sweep <- function(x, MARGIN, STATS, FUN = "-", check.margin=TRUE, ...)
 {
     FUN <- match.fun(FUN)
     dims <- dim(x)
+	if (check.margin) {
+		dimmargin <- dims[MARGIN]
+		dimstats <- dim(STATS)
+		lstats <- length(STATS)
+		if (lstats > prod(dimmargin)) {
+			warning("length of STATS greater than the extent of dim(x)[MARGIN]")
+		} else if (is.null(dimstats)) { # STATS is a vector
+			cumDim <- c(1, cumprod(dimmargin))
+			upper <- min(cumDim[cumDim >= lstats])
+			lower <- max(cumDim[cumDim <= lstats])
+			if (upper %% lstats != 0 || lstats %% lower != 0)
+				warning("STATS does not recycle exactly across MARGIN")
+		} else {
+			dimmargin <- dimmargin[dimmargin > 1]
+			dimstats <- dimstats[dimstats > 1]
+			if (length(dimstats) != length(dimmargin) || any(dimstats != dimmargin))
+				warning("length(STATS) or dim(STATS) do not match dim(x)[MARGIN]")
+		}
+	}
     perm <- c(MARGIN, (1:length(dims))[ - MARGIN])
     FUN(x, aperm(array(STATS, dims[perm]), order(perm)), ...)
 }
--- R-devel_2007-08-06/src/library/base/man/sweep.Rd	2007-07-27 17:51:35.000000000 +0200
+++ R-devel_2007-08-06-sweep/src/library/base/man/sweep.Rd	2007-08-07 10:29:45.517757200 +0200
@@ -11,7 +11,7 @@
   statistic.
 }
 \usage{
-sweep(x, MARGIN, STATS, FUN="-", \dots)
+sweep(x, MARGIN, STATS, FUN="-", check.margin=TRUE, \dots)
 }
 \arguments{
   \item{x}{an array.}
@@ -22,8 +22,18 @@
     case of binary operators such as \code{"/"} etc., the function name
     must backquoted or quoted. (\code{FUN} is found by a call to
     \code{\link{match.fun}}.)}
+  \item{check.margin}{logical. If \code{TRUE} (the default), warn if the
+    length or dimensions of \code{STATS} do
+    not match the specified dimensions of \code{x}.}
   \item{\dots}{optional arguments to \code{FUN}.}
 }
+\details{
+  The consistency check among \code{STATS}, \code{MARGIN} and \code{x}
+  is stricter if \code{STATS} is an array than if it is a vector.
+  In the vector case, some kinds of recycling are allowed without a
+  warning. Use \code{sweep(x,MARGIN,as.array(STATS))} if \code{STATS}
+  is a vector and you want to be warned if any recycling occurs.
+}
 \value{
   An array with the same shape as \code{x}, but with the summary
   statistics swept out.