I would like to bootstrap the difference between two mean costs (I have a different number of observations in the two group costs under consideration).
So, this is my script: x <- datos$direct_costsUS fun <- function(x){m=(mean(x[63:136])-mean(x[1:62])) } boot.x<- boot(x, statistic = function(d, ind){fun(d[ind])}, R = 5000, sim = "ordinary") boot.ci(boot.x, conf = 0.95,type = c("norm","basic","perc","bca")) ####Problem with bca plot(boot.x) This is the final result: Bootstrap Statistics : original bias std. error t1* 15.95379 -15.95875 4.792771 the bias sounds to me really strange. Do you think my bootstrap procedure is working well? Thanks a lot for your time. Best Regards. Marcella -- View this message in context: http://r.789695.n4.nabble.com/Bootstrap-tp2317776p2317776.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.