Hi there, You need a function for your statistic:
> boot(x, function(x, index) mean(x[index]), R = 1000) ORDINARY NONPARAMETRIC BOOTSTRAP Call: boot(data = x, statistic = function(x, index) mean(x[index]), R = 1000) Bootstrap Statistics : original bias std. error t1* 0.4069613 0.005465687 0.07355997 See http://www.mayin.org/ajayshah/KB/R/documents/boot.html for more information and examples. HTH, Jorge.- On Fri, Jun 7, 2013 at 6:03 PM, Rguy <r...@123mail.org> wrote: > I am getting started with the boot package and boot command. As a first > step I tried the following. Something is wrong, but i can't see what. Any > advice would be much appreciated. > > > x = runif(10) > > mean(x) > [1] 0.467626212374307 > > boot(x, mean, R=100) > Error in mean.default(data, original, ...) : > 'trim' must be numeric of length one > > Enter a frame number, or 0 to exit > > 1: boot(x, mean, R = 100) > 2: statistic(data, original, ...) > 3: mean.default(data, original, ...) > 4: stop("'trim' must be numeric of length one") > 5: (function () > { > utils::recover() > })() > > When I enter a trim parameter I get the following: > > > boot(x, mean, R=100, trim=0) > [...some output omitted...] > Warning in if (na.rm) x <- x[!is.na(x)] : > the condition has length > 1 and only the first element will be used > Warning in if (na.rm) x <- x[!is.na(x)] : > the condition has length > 1 and only the first element will be used > Warning in if (na.rm) x <- x[!is.na(x)] : > the condition has length > 1 and only the first element will be used > Warning in if (na.rm) x <- x[!is.na(x)] : > the condition has length > 1 and only the first element will be used > Warning in if (na.rm) x <- x[!is.na(x)] : > the condition has length > 1 and only the first element will be used > Warning in if (na.rm) x <- x[!is.na(x)] : > the condition has length > 1 and only the first element will be used > Warning in if (na.rm) x <- x[!is.na(x)] : > the condition has length > 1 and only the first element will be used > Warning in if (na.rm) x <- x[!is.na(x)] : > the condition has length > 1 and only the first element will be used > > ORDINARY NONPARAMETRIC BOOTSTRAP > > > Call: > boot(data = x, statistic = mean, R = 100, trim = 0) > > > Bootstrap Statistics : > original bias std. error > t1* 0.467626212374307 0 0 > > > > When I enter an na.rm value as well the following is output: > > > boot(x, mean, R=100, trim=0, na.rm=T) > > ORDINARY NONPARAMETRIC BOOTSTRAP > > > Call: > boot(data = x, statistic = mean, R = 100, trim = 0, na.rm = T) > > > Bootstrap Statistics : > original bias std. error > t1* 0.467626212374307 0 0 > > > > Notice that the standard error is 0, indicating that no bootstrapping has > actually taken place. > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.