Hello, d <- data.frame(a=c(2,3,4), b=c(2,4,1), c=c(3,5,6))
## one NA s.r <- sample(dim(d)[1], 1) s.c <- sample(dim(d)[2], 1) d.na <- d d.na[s.r, s.c] <- NA d.na # Here a matrix is more comfortable by using sample. For multiple NA, you should write a loop, but to choose e.g. exact 4 values, it might be, that one value is more than one times chosen. For this purpose you can search at your NA by using which(is.na(d), arr.ind=TRUE) and count only if those index is not a NA at a while loop. This is not an elegant way, but probably it helps you a little bit. Best, Matthias > -----Urspr�ngliche Nachricht----- > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Im Auftrag von > Caroline TRUNTZER > Gesendet: Dienstag, 01. M�rz 2005 15:04 > An: [email protected] > Betreff: [R] Help : delete at random > > > Hello > I would like to delete some values at random in a data frame. > Does anyone know how I could do? With best regards Caroline > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read > the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
