[Ana Conesa] > I am looking for a function/way to get the array coordinates of given > elements in an array. What I mean is the following: > - Let X be a 3D array > - I find the ordering of the elements of X by ord <- order(X) > (this returns me a vector) > - I now want to find the x,y,z coordinates of each element of ord
[Moshe Olshansky] >If your array's dimensions were KxMxN and the "linear" >index is i then >n <- ceiling(i/(K*M)) >i1 <- i - (n-1)*(K*M) >m <- ceiling(i1/K) >k <- i1 - (m-1)*K >and your index is (k,m,n) The reshape package might be helpful, here. If I understand the problem correctly, given this artificial example: X <- sample(1:24) dim(X) <- c(2, 3, 4) you would want: library(reshape) melt(X)[order(X), -4] so getting the indices in a three columns data frame. -- François Pinard http://pinard.progiciels-bpi.ca ______________________________________________ R-help@stat.math.ethz.ch 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.
