R語言-檢視變數及資料型態所佔記憶體容量，零成本提高計算效率

原始文章

來吧，直接複製貼上

check_file_size <- function(name){

  size <- object.size(get(name))

  # 4496535920 bytes = 4496 mb
  if(size >= 1000000){
    unit_size <- 1000000
    unit <- "mb"
  }else if(size >= 1000){
    unit_size <- 1000
    unit <- "kb"
  }else{
    unit_size <- 1
    unit <- "byte"
  }

  size <- size / unit_size
  size <- round(size)
  cat(paste0(name, " ", size, " ", unit))
}

檢查資料型態(Data Type)的容量大小

# Compare Date and Number
> t1 <- Sys.Data()
> t2 <- 20200101
> check_file_size("t1", unit = "byte")
t1 256 byte
> check_file_size("t2",unit = "byte")
t2 48 byte

# Compare numeric and character for ID
> test <- as.numeric(870576)
> test2 <- as.character(870576)
> check_file_size("test", unit = "byte")
test 48 byte
> check_file_size("test2", unit = "byte")
test2 96 byte