Don't know what exactly you're trying to do, but you make a matrix with 11 columns and 50 rows, then treat it as a vector. On top of that, you try to fill 50 rows/columns with 50 values. Off course that doesn't work. Did you check the warning messages when running the code?
Either do : for(i in c(1:11)){ set[,i] <-sample(x,50) print(c(i,"->", set), quote = FALSE) } or for(i in c(1:50)){ set[i,] <-sample(x,11) print(c(i,"->", set), quote = FALSE) } Or just forget about the loop altogether and do : set <- replicate(11,sample(x,50)) or set <- t(replicate(50,sample(x,11))) cheers On Thu, Jul 8, 2010 at 8:04 AM, Assa Yeroslaviz <fry...@gmail.com> wrote: > Hello R users, > > I'm trying to extract random samples from a big array I have. > > I have a data frame of over 40k lines and would like to produce around 50 > random sample of around 200 lines each from this array. > > this is the matrix > ID xxx_1c xxx__2c xxx__3c xxx__4c xxx__5T xxx__6T xxx__7T xxx__8T > yyy_1c yyy_1c _2c > 1 A_512 2.150295 2.681759 2.177138 2.142790 2.115344 2.013047 > 2.115634 2.189372 1.643328 1.563523 > 2 A_134 12.832488 12.596373 12.882581 12.987091 11.956149 11.994779 > 11.650336 11.995504 13.024494 12.776322 > 3 A_152 2.063276 2.160961 2.067549 2.059732 2.656416 2.075775 > 2.033982 2.111937 1.606340 1.548940 > 4 A_163 9.570761 10.448615 9.432859 9.732615 10.354234 10.993279 > 9.160038 9.104121 10.079177 9.828757 > 5 A_184 3.574271 4.680859 4.517047 4.047096 3.623668 3.021356 > 3.559434 3.156093 4.308437 4.045098 > 6 A_199 7.593952 7.454087 7.513013 7.449552 7.345718 7.367068 > 7.410085 7.022582 7.668616 7.953706 > ... > > I tried to do it with a for loop: > > genelist <- read.delim("/user/R/raw_data.txt") > rownames(genelist) <- genelist[,1] > genes <- rownames(genelist) > > x <- 1:40000 > set <- matrix(nrow = 50, ncol = 11) > > for(i in c(1:50)){ > set[i] <-sample(x,50) > print(c(i,"->", set), quote = FALSE) > } > > which basically do the trick, but I just can't save the results outside the > loop. > After having the random sets of lines it wasn't a problem to extract the > line from the arrays using subset. > > genSet1 <-sample(x,50) > random1 <- genes %in% genSet1 > subsetGenelist <- subset(genelist, random1) > > > is there a different way of creating these random vectors or saving the loop > results outside tjhe loop so I cn work with them? > > Thanks a lot > > Assa > > [[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. > -- Joris Meys Statistical consultant Ghent University Faculty of Bioscience Engineering Department of Applied mathematics, biometrics and process control tel : +32 9 264 59 87 joris.m...@ugent.be ------------------------------- Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php ______________________________________________ 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.