Hi David, If you mean that you have two data frames named x and y and want the correlations between the columns that would be on the diagonal of a correlation matrix:
r<-list() for(i in 1:n) r[[i]]<-cor(x[,i],y[,i]) If I'm wrong, let me know. Jim On Mon, Sep 10, 2018 at 3:06 PM David Disabato <ddisa...@gmail.com> wrote: > > 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. ______________________________________________ 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.