Clarify role of fun.data. Closes #929

Author: hadley

R/stat-summary.r

@@ -1,9 +1,11 @@
 #' Summarise y values at every unique x.
 #'
 #' \code{stat_summary} allows for tremendous flexibilty in the specification
-#' of summary functions.  The summary function can either operate on a data
-#' frame (with argument name \code{fun.data}) or on a vector (\code{fun.y},
-#' \code{fun.ymax}, \code{fun.ymin}).
+#' of summary functions. The summary function can either supply individual
+#' summary functions for each of y, ymin and ymax (with \code{fun.y},
+#' \code{fun.ymax}, \code{fun.ymin}), or return a data frame containing any
+#' number of aesthetiics with with \code{fun.data}. All summary functions
+#' are called with a single vector of values, \code{x}.
 #'
 #' A simple vector function is easiest to work with as you can return a single
 #' number, but is somewhat less flexible.  If your summary function operates

man/stat_summary.Rd

@@ -36,9 +36,11 @@ a data.frame with additional columns:
 }
 \description{
 \code{stat_summary} allows for tremendous flexibilty in the specification
-of summary functions.  The summary function can either operate on a data
-frame (with argument name \code{fun.data}) or on a vector (\code{fun.y},
-\code{fun.ymax}, \code{fun.ymin}).
+of summary functions. The summary function can either supply individual
+summary functions for each of y, ymin and ymax (with \code{fun.y},
+\code{fun.ymax}, \code{fun.ymin}), or return a data frame containing any
+number of aesthetiics with with \code{fun.data}. All summary functions
+are called with a single vector of values, \code{x}.
 }
 \details{
 A simple vector function is easiest to work with as you can return a single