Hi list, In a function I am writing, I need to extract the dimension names of an array. I know this can be acheived easily using dimnames() but my problem is that I want my function to be robust when the number of dimensions varies. Consider the following case:
foo <- array(data = rnorm(32), dim = c(4,4,2), dimnames=list(letters[1:4], LETTERS[1:4], letters[5:6])) # What I want is to extract the *names of the dimensions* for which foo have positive values: ind <- which(foo > 0, arr.ind = TRUE) # A first solution is: t(apply(ind, 1, function(x) unlist(dimnames(foo[x[1], x[2], x[3], drop=FALSE])))) # But it does require to know the dimensions of foo I would like to do something like: ind <- which(foo > 0, arr.ind = TRUE) t(apply(ind, 1, function(x) unlist(dimnames(foo[x, drop=FALSE])))) but in that case the dimnames are dropped. Any suggestion? Cheers, Pierre -- Scientist Landcare Research, New Zealand ______________________________________________ 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.
