merge_purr.R

library(purrr)
library(dplyr)


dump_data_frame <- function(i) {
  return(data.frame(
    a = rep.int(i, i * 1000000),
    b = rep.int(i * 2, i * 1000000),
    c = rep.int(i * 3, i * 1000000),
    d = rep.int(i * 4, i * 1000000)
  ))
}

list_data_frame <- map(c(1,2,3,4,5), dump_data_frame)



ptm <- proc.time()
last_data_frame <- reduce(list_data_frame, function(x, y) {
  return(bind_rows(x, y))
})
proc.time() - ptm


ptm <- proc.time()
last_data_frame <- reduce(list_data_frame, function(x, y) {
  return(rbind(x, y))
})
proc.time() - ptm