Hi, dat <- read.table(text="Date A B C D 1-Jan-61 0.00 1.27 8.128 0.25 2-Jan-61 6.10 9.144 94.742 15.49 3-Jan-61 0.00 0.508 1.27 0.00 4-Jan-61 0.00 0 NA 0.00 5-Jan-61 0.00 0 0 0.00 6-Jan-61 0.00 NA 0 0.00 7-Jan-61 0.00 0 0 0.00 8-Jan-61 0.00 NA 0 0.00 9-Jan-61 0.00 NA 0 NA 10-Jan-61 0.00 4.064 4.826 0.76",sep="",header=TRUE,stringsAsFactors=FALSE)
res <- as.data.frame(apply(dat[,-1],2,FUN=function(x) {x1 <-dat[,1][is.na(x)]; x2 <- max(colSums(is.na(dat[,-1]))); if(length(x1) < x2) c(x1, rep("",x2-length(x1))) else x1}),stringsAsFactors=FALSE) A.K. On Wednesday, March 19, 2014 2:39 PM, eliza botto <eliza_bo...@hotmail.com> wrote: Dear R-Family, I have a data-set of the following format. I am only presenting a part of it. Date A B C D 1-Jan-61 0.00 1.27 8.128 0.25 2-Jan-61 6.10 9.144 94.742 15.49 3-Jan-61 0.00 0.508 1.27 0.00 4-Jan-61 0.00 0 NA 0.00 5-Jan-61 0.00 0 0 0.00 6-Jan-61 0.00 NA 0 0.00 7-Jan-61 0.00 0 0 0.00 8-Jan-61 0.00 NA 0 0.00 9-Jan-61 0.00 NA 0 NA 10-Jan-61 0.00 4.064 4.826 0.76 You can see that each column has some NAs in it, What i want to do is to learn that which date has NA for each column. Here it should be something like the following A B C D 6-Jan-61 4-Jan-61 9-Jan-61 8-Jan-61 9-Jan-61 Thankyou very much in advance Eliza [[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.