Hi R-help, I am trying to create a for loop with multiple iteration indexes. I don't want to use two different for loops nested together because I don't need the full matrix of the two indexes, just the diagonal elements (e.g., i[1] & j[1] and i[2] & j[2], but not i[1] & j[2]). Is there a way to specify both i and j in a single for loop? Here is a simplified example of pseudo-code where x and y are equally sized character vectors with column names and dat is their dataframe (obviously this code doesn't run in R, but hopefully you perceive my goal):
r <- list() n <- 0 for (i in x; j in y) { n <- n + 1 r[[n]] <- cor(x = dat[, i], y = dat[, j]) } print(r) I realize there are other solutions to this particular correlation example, but my actual problem is much more complicated, so I am hoping for a solution that generalizes across any code within the for loop. -- David J. Disabato, M.A. Clinical Psychology Doctoral Student George Mason University ddisa...@gmu.edu Email is not a secure form of communication as information and confidentiality cannot be guaranteed. Information provided in an email is not intended to be a professional service. In the case of a crisis or emergency situation, call 911. [[alternative HTML version deleted]] ______________________________________________ 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.