From 7d2096855edcc196629c1c7a9983a56ec6addd1e Mon Sep 17 00:00:00 2001 From: Johannes Ranke Date: Fri, 24 Apr 2015 02:21:04 +0200 Subject: Add a geometric mean function --- pkg/R/geomean.R | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 pkg/R/geomean.R (limited to 'pkg/R/geomean.R') diff --git a/pkg/R/geomean.R b/pkg/R/geomean.R new file mode 100644 index 0000000..626829b --- /dev/null +++ b/pkg/R/geomean.R @@ -0,0 +1,38 @@ +# Copyright (C) 2015 Johannes Ranke +# Contact: jranke@uni-bremen.de +# This file is part of the R package pfm + +# 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 3 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. + +# You should have received a copy of the GNU General Public License along with +# this program. If not, see + +#' Calculate the geometric mean +#' +#' Based on some posts in a thread on Stackoverflow +#' \url{http://stackoverflow.com/questions/2602583/geometric-mean-is-there-a-built-in} +#' This function checks for negative values, removes NA values per default and +#' returns 0 if at least one element of the vector is 0. +#' +#' @param x Vector of numbers +#' @param na.rm Should NA values be omitted? +#' @return The geometric mean +#' @export +#' @author Johannes Ranke +#' @examples +#' geomean(c(1, 3, 9)) +#' geomean(c(1, 3, NA, 9)) +#' \dontrun{geomean(c(1, -3, 9)) # returns an error} +geomean = function(x, na.rm = TRUE){ + if (any(is.na(x)) & na.rm == FALSE) stop("Removal of NA values was not requested") + if (any(x < 0, na.rm = na.rm)) stop("Only defined for positive numbers") + exp(mean(log(x), na.rm = na.rm)) +} -- cgit v1.2.1