Here is an R tip. Use loop indices to avoid for()-loops damaging classes. Below is an R annoyance that occurs again and again: vectors lose class attributes when you iterate over them in a for()-loop. d <- c(Sys.time(), Sys.time()) print(d) #> "2018-02-18 10:16:16 PST" "2018-02-18 10:16:16 PST" for(di in... Read more