Dictionaries and pairs

Question

In R I was wondering if I could have a dictionary (in a sense like python) where I have a pair (i, j) as the key with a corresponding integer value. I have not

Answer 1

Both named lists and environments provide a mapping, but between a character string (the name, which acts as a key) and an arbitrary R object (the value). If your i and j are simple (as they appear in your example to be, being integers), you can easily make a unique string out of the pair of them by concatenating them with some delimiter. This would make a valid name/key

mykey <- function(i, j) {
  paste(i, j, sep="|")
}

maps <- list()
for(i in 1: 5) {  
  for(j in 2: 4) {
    maps[mykey(i,j)] <- which.min(someVector)
  }
}

You can extract any value for a specific i and j with

maps[[mykey(i,j)]]