Folks, I have a data frame with 4861469 rows that contains an ip address xxx.xxx.xxx.xxx as one of the columns. I want to assign a site to each row based on IP ranges. To do this I have a function to split the ip address as character into class A,B,C and D components. It works but is horribly inefficient in terms of speed. I can't quite see how one of the l/s/m/t/apply functions could be brought to bear on the problem. Does anyone have any thoughts?
for(i in 1:4861469) { lst <-unlist(strsplit(data$ComputerName[i], "\\.")) data$IPA[i] <-lst[[1]] data$IPB[i] <-lst[[2]] data$IPC[i] <-lst[[3]] data$IPD[i] <-lst[[4]] rm(lst) } Andrew Andrew Roberts Children's Orthopaedic Surgeon RJAH, Oswestry, UK [[alternative HTML version deleted]] ______________________________________________ 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.