Hi Troels, Not sure this is what you want.
> X<-runif(9,0,10) > FF1<-data.frame(ID=c(1,2,3)[rep(c(1,1,1,2,2,2,3,3,3))], > PERIOD=c(1,2,3)[rep(c(1,2,3),times=3)],X=X) > FF1$X[4]<-NA > FF1 ID PERIOD X 1 1 1 8.27119347 2 1 2 9.64698097 3 1 3 2.74132386 4 2 1 NA 5 2 2 4.29322683 6 2 3 5.09269667 7 3 1 4.07936332 8 3 2 7.41808455 9 3 3 0.01558664 A.K. ----- Original Message ----- From: Troels Ring <tr...@gvdnet.dk> To: r-help@r-project.org Cc: Sent: Wednesday, May 16, 2012 11:56 AM Subject: [R] simple data.frame question Dear friends - I hope you will forgive me another simple question, illustrated by ID <- c(1,1,1,2,2,3,3,3) PERIOD <- c(1,2,3,2,3,1,2,3) X <- runif(8,0,10)) FF <- data.frame(ID=ID,PERIOD=PERIOD,X=X) I need to the fourth value of X as NA, and ID and PERIOD is updated to 1,1,1,2,2,2,3,3,3 and 1,2,3,1,2,3,1,2,3 respectively. How do I use the pattern in ID and PERIOD to find the lacking X and put NA? Best wishes Troels Ring, Aalborg, Denmark ______________________________________________ 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.
