Modifying a vector in an object

modify_vector.R

## Modifying a vector in a parent environment

## This tests whether it's faster to use `self` or not, and whether it's faster to use `<-` vs `<<-`.

foo <- local({
  x <- integer()
  self <- environment()
  
  # Four different ways of setting a value:
  #  * With and without using `self`
  #  * With `<-` or with `<<-`
  list(
    set_self_single = function(i, value) {
      self$x[i] <- value
    },
    set_self_double = function(i, value) {
      self$x[i] <<- value
    },
    set_noself_single = function(i, value) {
      x[i] <- value
    },
    set_noself_double = function(i, value) {
      x[i] <<- value
    },
    reset = function() {
      self$x <- integer()
    }
  )
})

n <- 10000

system.time({
  foo$reset()
  for (i in seq_len(n)) foo$set_self_single(i, i)
})
#>   user  system elapsed 
#>  0.189   0.049   0.237 

system.time({
  foo$reset()
  for (i in seq_len(n)) foo$set_self_double(i, i)
})
#>   user  system elapsed 
#>  0.191   0.042   0.234 

system.time({
  foo$reset()
  for (i in seq_len(n)) foo$set_noself_single(i, i)
})
#>   user  system elapsed 
#>  0.073   0.021   0.094 

system.time({
  foo$reset()
  for (i in seq_len(n)) foo$set_noself_double(i, i)
})
#>   user  system elapsed 
#>  0.017   0.000   0.016 

profile.R

profvis::profvis({
  foo <- local({
    x <- integer()
    self <- environment()
    
    # Four different ways of setting a value:
    #  * With and without using `self`
    #  * With `<-` or with `<<-`
    list(
      set_self_single = function(i, value) {
        self$x[i] <- value
      },
      set_self_double = function(i, value) {
        self$x[i] <<- value
      },
      set_noself_single = function(i, value) {
        x[i] <- value
      },
      set_noself_double = function(i, value) {
        x[i] <<- value
      },
      reset = function() {
        self$x <- integer()
      }
    )
  })
  
  
  foo$reset()
  for (i in seq_len(n)) foo$set_self_single(i, i)
  
  foo$reset()
  for (i in seq_len(n)) foo$set_self_double(i, i)
  
  foo$reset()
  for (i in seq_len(n)) foo$set_noself_single(i, i)
  
  foo$reset()
  for (i in seq_len(n)) foo$set_noself_double(i, i)
})