Dear Seyit, You might consider the boot package in this situation. Here is an example:
require(boot) DF<-data.frame(Xvar,Yvar) temp <- boot(DF, function(DF,d){ S <- DF[d,] cor(S$Xvar,S$Yvar) }, R = 5000) temp$t0 # [1] 0.617422 max(temp$t) # [1] 0.7783784 hist(temp$t) Once you load the boot package, take a look at ?boot. HTH, Jorge On Tue, Apr 21, 2009 at 4:53 AM, Seyit Ali Kayis <s_a_ka...@hotmail.com>wrote: > > Dear R users, > > I need to do sampling without replacement (bootstraps). I have two > variables (Xvar, Yvar). > I have a correlation from original data set cor(Xvar, Yvar)=0.6174221. I am > doing 50000 sampling, > and in each sampling calculating correlations, saving, sorting and > getting 95% cutt off point (0.1351877). > I am getting maximum value as 0.3507219 (much smaller than correlation of > my original data). > I repeated the sampling a couple of time and none of them produced a > correlation > coefficient higher than my original data set. However, if I sort out my > Xvar and Yvar and > obtain correlation it is 0.9657125 which is much higher than correlation > for my original data. > I am doing sampling in another program and getting at least 1% higher > correlation than mine. > Now I am getting confused with sampling(random data) in R. My data and > codes for the scenario above are > in the attached file. I want to understand where I am making a mistake. Any > comment is deeply appreciated. > > Kind Regards > > Seyit Ali > > > > ------------------------------------------------------------------------------------------------------------------ > Dr. Seyit Ali KAYIS > Selcuk University > Faculty of Agriculture > Kampus, Konya, TURKEY > > s_a_ka...@yahoo.com, s_a_ka...@hotmail.com > Tell: +90 332 223 2830 Mobile: +90 535 587 1139 Fax: +90 332 241 0108 > > Greetings from Konya, TURKEY > http://www.ziraat.selcuk.edu.tr/skayis/ > > ---------------------------------------------------------------------------------------------------------------------- > > > > > > > _________________________________________________________________ > No-one wants to be lonely this Autumn Find someone to snuggle up with > > > Fchannel%2Findex%2Easpx%3Ftrackingid%3D1048628&_t=773568480&_r=nzWINDOWSliveMAILemailTAGLINES&_m=EXT > ______________________________________________ > 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.