[R] mapply & assign to generate functions

J Toll jctoll at gmail.com
Mon Mar 12 18:47:10 CET 2012


I have a problem that I'm finding a bit tricky.  I'm trying to use
mapply and assign to generate curried functions.  For example, if I
have the function divide

divide <- function(x, y) {
  x / y

And I want the end result to be functionally equivalent to:
half <- function(x) divide(x, 2)
third <- function(x) divide(x, 3)
quarter <- function(x) divide(x, 4)

But I want to do it using mapply and assign:
       c("half", "third", "quarter"),
       lapply(2:4, function(i) {function(x) divide(x, i)}),
       pos = 1)

The problem is in the third line.  I end up with 3 functions that are
all functionally equivalent to quarter().  Any suggestions on how to
get this to work properly.



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