Creating a function with a FUN input in r

Question

I am looking to make a function where the user can enter their own model selection function as an input to be used. I'm having trouble with finding the answer as I keep getting search results about how to make a simple R function, as opposed to an input much like the apply family.

Here is an example similar to what I am looking for but not quite:

simple<- function(mod, FUN){
  switch(FUN,
         AIC = AIC(mod),
         BIC = BIC(mod))
}
simple(lm(rnorm(100) ~ rnorm(100,4)), "AIC")

The above code runs but I must plan for all of the possible functions and write them within switch. I also am forced to write "AIC" as opposed to simply AIC.

Any thoughts to how I can create the function I am looking for? Let me know if you need additional information.

Answer 1

Something like this:

simple<- function(mod, FUN){
  FUN <- match.fun(FUN)
  FUN(mod)
}

simple(lm(rnorm(100) ~ rnorm(100,4)),FUN =  "BIC")

match.fun accepts a function, symbol or character, so there is some flexibility in how the FUN argument is passed.

An option for passing multiple functions, as mentioned in the comments:

simple <- function(mod, FUN){
  FUNS <- lapply(FUN,match.fun)
  lapply(FUNS,function(fun) fun(mod))
}