Your problem is that some bootstrap samples have no variation in x at all. How can you expect a sensible answer from such a sample?
On Thu, 13 May 2004, Hwange Project wrote: > I'm fighting with the following problem : > I want to do bootstrapping on a Kendall correlation with the following code Using package boot, uncredited! > > cor.function <- function(data,i) cor(data[i, 1], data[i, > 2],method="kendall") > > boot.ci <- boot.ci(boot.cor <- boot(cbind(x,y),cor.function, > R=1000),conf=c(0.95,0.99)) > > However, I've got problems because I've got ties in my x variables : > for example, it does not work with : > > x <- > c(8.67,3.67,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,6.80,0.00,0.00,3.96) > y <- c(329,264,274,339,302,334,334,312,355,327,287,319,361,355) > cor.function <- function(data,i) cor(data[i, 1], data[i, > 2],method="kendall") > boot.ci <- boot.ci(boot.cor <- boot(cbind(x,y),cor.function, > R=1000),conf=c(0.95,0.99)) > > I would appreciate any advice, even of changing from kendall to something > else, knowing that my x variables have a lot of ties and is far from > normally distributed. Given that you haven't told us your objective, we cannot help you choose anything better. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
