I want to replace column c3 with values from column c2 whenever values of column Id are 2. In stata I could use replace c3 = c2 if id ==2. How could I do that in R?
Thanks Sample data found below: > dput(df4) structure(list(c2 = c(42L, 42L, 47L, 47L, 55L, 55L, 36L, 36L, 61L, 61L), c3 = c(68L, 59L, 68L, 50L, 62L, 50L, 63L, 45L, 65L, 45L), id = c(1, 2, 1, 2, 1, 2, 1, 2, 1, 2)), datalabel = "Written by R. ", time.stamp = "23 Mar 2015 13:54", .Names = c("c2", "c3", "id"), formats = c("%9.0g", "%9.0g", "%9.0g"), types = c(253L, 253L, 255L), val.labels = c("", "", ""), var.labels = c("", "", ""), row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10"), version = 12L, class = "data.frame") ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.