Save/Load R Objects as .RDS files.

These functions wrap base::saveRDS() and base::readRDS() and are augmented with utility functions to make saving and loading R (.RDS) objects easier.

save_object(x, path, filename_modifier = NULL, sep = "_")

load_object(x, path, filename_modifier = NULL, sep = "_", auto_assign = TRUE)

Arguments

x	The R object to save.
path	A directory within the current RStudio Project.
filename_modifier	The saved .RDS file name takes on the R object's name by default (when filename_modifier = NULL). Optionally, a filename extension can be added, such as a random string or date. See examples for more details.
sep	Ignored by default. If filename_modifier is used, this is a character string used to separate the object name and modifier when writing the .RDS file.
auto_assign	Only for load_object() and TRUE by default. Should the object loaded automatically be assigned to the parent environment?

Value

Either a .RDS file written to the specified location or an R object containing the contents of the .RDS file.

Details

Specifically, these functions assume the use of an RStudio Project. The main benefit of these functions is the consistency between the name of the R object and the .RDS file name.

Additionally, for analyses where there are lots of objects to be saved/loaded, there are utilities to specify where these objects will be, e.g. set_object_path.

See also

set_object_path, get_object_oath, unset_object_path

Examples

if (interactive()) {
  library(fs)
  library(here)
  library(waldo)

  # Create a directory test-folder in the current RStudio Project path
  dir_create(here("test-folder"))

  # Save `mtcars` object to test-folder `here::here()` is run within
  # save_object, so it doesn't need to be supplied here, though it can be.
  save_object(mtcars, path = "test-folder")

  # Check the objects saved. The .RDS file is automatically named with the object's name
  # `mtcars.RDS`
  dir_ls(here('test-folder'))

  # The object can be loaded easily as:
  # This automatically assigns the object loaded as mtcars.
  load_object(mtcars, path = "test-folder")

  # If you wish to assign an object yourself,
  # for example as a different name, this can be done as follows:
  carsmt <- load_object(mtcars, path = "test-folder", auto_assign = FALSE)

  # .RDS files can also have a modifier to distinguish between similar R objects.
  mtcars <- mtcars[,1:3]
  save_object(mtcars, path = "test-folder",
              filename_modifier = "cols_1-3", sep = "_")

  # It can be loaded back with the same arguments
  load_object(mtcars, path = "test-folder",
              filename_modifier = "cols_1-3", sep = "_")

  # It could also be loaded back directly by name (should be character vector)
  load_object("mtcars_cols_1-3", path = "test-folder")

  # For analyses where lots of objects will be reused, you can set the
  # global path option and not specifically include the path.
  set_object_path("test-folder")

  # This now works! No path necessary.
  save_object(iris)
  load_object(iris)

  # Custom filenames also work:
  save_object(iris, filename_modifier = "123")
  load_object(iris, filename_modifier = "123")

  # You can still specify an alternative path even with that global option set.
  dir_create("another-test-folder")

  # Modify iris for example
  iris$message <- "I'm in a new folder"

  # Save modified iris to the new path
  save_object(iris, path = "another-test-folder")
  load_object(iris, path = "another-test-folder")

  # Let's compare these
  orig <- load_object(iris, auto_assign = FALSE)
  new <- load_object(iris, path = "another-test-folder", auto_assign = FALSE)

  # Should not be identical!
  compare(orig, new)

  # Check the path
  get_object_path()

  # Unset the path
  unset_object_path()

}