Hi Steven, You code has two problems. One is loop structure which should be for(i in 1:length). The second is that you loop the process twice (for and sapply).
Hope followed code will work. for (i in 1:length(ind)) { x <- dat$Close_date[i] dat[["Flag"]][i] <- ifelse((x >= oc[ind[[i]], 1] & x < oc[ind[[i]], 2]) | (x >= oc[ind[[i]], 3] & x < oc[ind[[i]], 4]) | (x >= oc[ind[[i]], 5] & x < oc[ind[[i]], 6]), "Valid", "Invalid") } Yours, Wu ----- A R learner. -- View this message in context: http://r.789695.n4.nabble.com/apply-family-functions-tp2315905p2317287.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.