Something like: dat[dat$ID %in% sample(unique(dat$ID), 3), ]
Andy > From: [EMAIL PROTECTED] > > I have a data set that looks like the following: > ID Responce > 1 57 > 1 63 > 1 49 > 2 31 > 2 45 > 2 67 > 2 91 > 3 56 > 3 43 > 4 23 > 4 51 > 4 61 > 4 76 > 4 68 > 5 34 > 5 35 > 5 45 > I used sample(unique(ID)) to select a sample if ID's, say, > (1,4,5). Now > I want to pull out the rows with ID's 1, 4, and 5. I've > tried forceing > the matrix into a vector but it does not create and > appropriate vector. > I've also tried the if statment but it didn't work right either. Any > suggestions? > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html