load
Reload Saved Datasets
Reload datasets written with the function save.
- Keywords
- file
Usage
load(file, envir = parent.frame(), verbose = FALSE)Arguments
- file
- a (readable binary-mode) connection or a character string giving the name of the file to load (when tilde expansion is done).
- envir
- the environment where the data should be loaded.
- verbose
- should item names be printed during loading?
Details
load can load R objects saved in the current or any earlier
format. It can read a compressed file (see save)
directly from a file or from a suitable connection (including a call
to url).
A not-open connection will be opened in mode "rb" and closed
after use. Any connection other than a gzfile or
gzcon connection will be wrapped in gzcon
to allow compressed saves to be handled: note that this leaves the
connection in an altered state (in particular, binary-only), and that
it needs to be closed explicitly (it will not be garbage-collected).
Only R objects saved in the current format (used since R 1.4.0) can be read from a connection. If no input is available on a connection a warning will be given, but any input not in the current format will result in a error.
Loading from an earlier version will give a warning about the
‘magic number’: magic numbers 1971:1977 are from R <
0.99.0, and RD[ABX]1 from R 0.99.0 to R 1.3.1. These are all
obsolete, and you are strongly recommended to re-save such files in a
current format.
The verbose argument is mainly intended for debugging. If it
is TRUE, then as objects from the file are loaded, their
names will be printed to the console. If verbose is set to
an integer value greater than one, additional names corresponding to
attributes and other parts of individual objects will also be printed.
Larger values will print names to a greater depth.
Objects can be saved with references to namespaces, usually as part of
the environment of a function or formula. As from R 3.1.0 such
objects can be loaded even if the namespace is not available: it is
replaced by a reference to the global environment with a warning. The
warning identifies the first object with such a reference (but there
may be more than one).
Value
-
A character vector of the names of objects created, invisibly.
Warning
Saved R objects are binary files, even those saved with
ascii = TRUE, so ensure that they are transferred without
conversion of end of line markers. load tries to detect such a
conversion and gives an informative error message.
See Also
For other interfaces to the underlying serialization format, see
unserialize and readRDS.
Examples
library(base)
## save all data
xx <- pi # to ensure there is some data
save(list = ls(all = TRUE), file= "all.RData")
rm(xx)
## restore the saved values to the current environment
local({
load("all.RData")
ls()
})
## restore the saved values to the user's workspace
load("all.RData", .GlobalEnv)
unlink("all.RData")
## Not run:
# con <- url("http://some.where.net/R/data/example.rda")
# ## print the value to see what objects were created.
# print(load(con))
# close(con) # url() always opens the connection
# ## End(Not run)
Community examples
# Components in SAS = Packages in R # SAS Work Library = R Global Environment # Load the abalone dataset load("abalone.Rdata") setwd() # List the objects in memory ls() help() # Help function help(ls) sessionInfo() #provides details on computer system and packages loaded library() #used to load packages during your R session sessionInfo() # provides details on computer system and packages loaded # Load the dplyr package and run sessionInfo again library(dplyr) sessionInfo() help("load")