May be this helps: dat<- read.table(text=" ID Var 1 1 2 4 3 6 4 7 5 7 6 8 7 9 ",sep="",header=TRUE) dat$Date<-cumsum(seq_len(nrow(dat))%%2) dat # ID Var Date #1 1 1 1 #2 2 4 1 #3 3 6 2 #4 4 7 2 #5 5 7 3 #6 6 8 3 #7 7 9 4 A.K.
----- Original Message ----- From: Ye Lin <ye...@lbl.gov> To: R help <r-help@r-project.org> Cc: Sent: Tuesday, May 21, 2013 4:16 PM Subject: [R] add identifier column by row I want to add identifier column (Date) to a time series data frame. I want to name the "Date" column be from 1 to 30 every 1440 rows. Say I have a data like this (I simply my actual data here): $dat ID Var 1 1 2 4 3 6 4 7 5 7 6 8 How can I add identifier column (Date) from 1 to 3 every 2 rows and have output like this: ID Var Date 1 1 1 2 4 1 3 6 2 4 7 2 5 7 3 6 8 3 Thanks, [[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.
