Hi all, I'm working with a large data set (on the order of 300X300) and trying to apply a function which compares the elements of all possible 2x2 submatrices. There are rc(r-1)(c-1) such submatrices, so obviously the naive method of looping through the rows and columns is computationally unfeasible for my data set:
for(i in 1:(nrow(data)-1)) { for(j in (i+1):nrow(data)) { for (m in 1:(ncol(data)-1)) { for (n in (m+1):ncol(data)) { I have tried using the outer and apply functions to vectorize the task, but I can't seem to figure out the best method (or any method, for that matter) to help with what I'm trying to do. Any and all help is much appreciated! Thanks in advance, C -- View this message in context: http://r.789695.n4.nabble.com/Help-with-applying-a-function-to-all-possible-2x2-submatrices-tp4647048.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.