| # File src/library/stats/R/weighted.mean.R |
| # Part of the R package, https://www.R-project.org |
| # |
| # Copyright (C) 1995-2012 The R Core Team |
| # |
| # This program is free software; you can redistribute it and/or modify |
| # it under the terms of the GNU General Public License as published by |
| # the Free Software Foundation; either version 2 of the License, or |
| # (at your option) any later version. |
| # |
| # This program is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| # GNU General Public License for more details. |
| # |
| # A copy of the GNU General Public License is available at |
| # https://www.R-project.org/Licenses/ |
| |
| weighted.mean <- function(x, w, ...) UseMethod("weighted.mean") |
| |
| weighted.mean.default <- function(x, w, ..., na.rm = FALSE) |
| { |
| if(missing(w)) { |
| ## avoid creating weights vector |
| if (na.rm) x <- x[!is.na(x)] |
| return(sum(x)/length(x)) |
| } |
| if (length(w) != length(x)) |
| stop("'x' and 'w' must have the same length") |
| if (na.rm) { i <- !is.na(x); w <- w[i]; x <- x[i] } |
| sum((x*w)[w != 0])/sum(w) # --> NaN in empty case |
| } |
| |
| ## see note for ?mean.Date |
| weighted.mean.Date <- function (x, w, ...) |
| structure(weighted.mean(unclass(x), w, ...), class = "Date") |
| |
| weighted.mean.POSIXct <- function (x, w, ...) |
| .POSIXct(weighted.mean(unclass(x), w, ...), attr(x, "tzone")) |
| |
| weighted.mean.POSIXlt <- function (x, w, ...) |
| as.POSIXlt(weighted.mean(as.POSIXct(x), w, ...)) |
| |
| weighted.mean.difftime <- function (x, w, ...) |
| structure(weighted.mean(unclass(x), w, ...), |
| units = attr(x, "units"), class = "difftime") |