Look at ?sample for how to shuffle/permute a single vector (or rows of a data frame/matrix) and ?replicate for a way to do it a bunch of times and return the results in a nice form.
Hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of Yonatan Nissenbaum > Sent: Tuesday, September 01, 2009 1:35 AM > To: r-help@r-project.org > Subject: [R] permutation and reshuffling > > Hi, > > > > I'm looking for an efficient code that will enable me to reshuffle data > (phenotype) for certain number of individuals and creating a loop that > will > randomly simulate it for 10000 times *(permutation)*. I also need to > find > how I keep the information (p value for each SNP) gathered for all the > 10000 > iterations. > > My data set looks like this (n=500): > > Individual # > > Phenotype > > SNP1 > > SNP2 > > SNP3 > > SNP4 > > SNP5 > > SNP6 > > SNP7 > > SNP8 > > SNP9 > > SNP10 > > SNP11 > > SNP12 > > 1 > > 0 > > T > > T > > G > > G > > A > > C > > G > > T > > A > > A > > T > > C > > 2 > > 1 > > A > > T > > C > > G > > A > > C > > G > > T > > A > > G > > T > > C > > > > Many thanks, > > > > Jonathan > > [[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. ______________________________________________ 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.
