| % File src/library/stats/man/ave.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{ave} |
| \title{Group Averages Over Level Combinations of Factors} |
| \usage{ |
| ave(x, \dots, FUN = mean) |
| } |
| \alias{ave} |
| \arguments{ |
| \item{x}{A numeric.} |
| \item{\dots}{Grouping variables, typically factors, all of the same |
| \code{length} as \code{x}.} |
| \item{FUN}{Function to apply for each factor level combination.} |
| } |
| \description{ |
| Subsets of \code{x[]} are averaged, where each subset consist of those |
| observations with the same factor levels. |
| } |
| \value{ |
| A numeric vector, say \code{y} of length \code{length(x)}. |
| If \code{\dots} is \code{g1, g2}, e.g., |
| \code{y[i]} is equal to \code{FUN(x[j]}, for all \code{j} with |
| \code{g1[j] == g1[i]} and \code{g2[j] == g2[i])}. |
| } |
| \seealso{\code{\link{mean}}, \code{\link{median}}.} |
| \examples{ |
| require(graphics) |
| |
| ave(1:3) # no grouping -> grand mean |
| |
| attach(warpbreaks) |
| ave(breaks, wool) |
| ave(breaks, tension) |
| ave(breaks, tension, FUN = function(x) mean(x, trim = 0.1)) |
| plot(breaks, main = |
| "ave( Warpbreaks ) for wool x tension combinations") |
| lines(ave(breaks, wool, tension ), type = "s", col = "blue") |
| lines(ave(breaks, wool, tension, FUN = median), type = "s", col = "green") |
| legend(40, 70, c("mean", "median"), lty = 1, |
| col = c("blue","green"), bg = "gray90") |
| detach() |
| } |
| \keyword{univar} |
| |