Keep only specified objects in the environment, removing all others.

This function selectively retains the objects specified in the objects parameter in the current environment, removing all other objects. It is useful for memory management by clearing unnecessary objects from the environment. The function also provides an option to print the names of the kept and removed variables.

Usage

keep_only(objects, verbose = TRUE)

Arguments

objects: Character vector. Names of the objects to be kept in the environment.
verbose: Logical. Whether to print the names of kept and removed variables. Default to TRUE.

Value

No return value, called for side effects.

Author

Ahmed El-Gabbas

Examples

load_packages(terra)

A <- B <- C <- 15
ls()
#> [1] "A" "B" "C"

keep_only("A")
#> Removed Variables (2): 1:B ||  2:C
#> Kept Variables (1): 1:A

ls()
#> [1] "A"
rm(list = ls())


A <- B <- C <- 15
keep_only(c("A","B"))
#> Removed Variables (1): 1:C
#> Kept Variables (2): 1:A ||  2:B
ls()
#> [1] "A" "B"

# -------------------------------------------

# use inside a function
function1 <- function(a = 1, b = 2, c = 3) {
  z <- terra::rast()
  print(paste0("available objects before keep_only: ", toString(ls())))

  keep_only(c("a", "b"), verbose = FALSE)
  print(paste0("available objects after keep_only: ", toString(ls())))

  return(invisible(NULL))
}
function1()
#> [1] "available objects before keep_only: a, b, c, z"
#> [1] "available objects after keep_only: a, b"