| save {base} | R Documentation |
save writes an external representation of R objects to the
specified file. The objects can be read back from the file at a later
date by using the function load (or data in some cases).
save.image() is just a short-cut for “save my current
workspace”,
i.e., save(list = ls(all=TRUE), file = ".RData"). It is also what
happens with q("yes").
save(..., list = character(0),
file = stop("'file' must be specified"),
ascii = FALSE, version = NULL, envir = parent.frame(),
compress = !ascii, eval.promises = TRUE)
save.image(file = ".RData", version = NULL, ascii = FALSE,
compress = !ascii, safe = TRUE)
... |
the names of the objects to be saved. |
list |
A character vector containing the names of objects to be saved. |
file |
a connection or the name of the file where the data will be saved. Must be a file name for workspace format version 1. |
ascii |
if TRUE, an ASCII representation of the data is
written. The default value of ascii is FALSE which
leads to a more compact binary file being written. |
version |
the workspace format version to use. NULL
specifies the current default format. The version used from R
0.99.0 to R 1.3.1 was version 1. The default format as from R
1.4.0 is version 2. |
envir |
environment to search for objects to be saved. |
compress |
logical specifying whether saving to a named file is to
use compression. Ignored when file is a connection and for
workspace format version 1. |
eval.promises |
logical: should objects which are promises be forced before saving? |
safe |
logical. If TRUE, a temporary file is used for
creating the saved workspace. The temporary file is renamed to
file if the save succeeds. This preserves an existing
workspace file if the save fails, but at the cost of using
extra disk space during the save. |
The names of the objects specified either as symbols in ... or
as a character vector in list are used to look up the objects
from environment envir. By default promises are
evaluated, but if eval.promises = FALSE promises are saved
(together with their evaluation environments). (Promises embedded in
objects are always saved unevaluated.)
All R platforms use the XDR representation of binary objects in binary save-d files, and these are portable across all R platforms. (ASCII saves used to be useful for moving data between platforms but are now only of historical interest.)
Default values for the ascii, compress, safe and
version arguments can be modified with the save.defaults
option (used both by save and save.image), see also the
example section below. If a save.image.defaults option is set
it overrides save.defaults for function save.image
(which allows this to have different defaults).
It is possible to compress later (with gzip) a file saved with
compress = FALSE: the effect is the same as saving with
compress = TRUE.
The ... arguments only give the names of the objects
to be saved: they are searched for in the environment given by the
envir argument, and the actual objects given as arguments need
not be those found.
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 and of 8-bit characters. The lines
are delimited by LF on all platforms.
Although the default version has not changed since R 1.4.0, this does not mean that saved files are necessarily backwards compatible. You will be able to load a saved image into an earlier version of R unless use is made of later additions (for example, raw vectors or external pointers).
The defaults were changed to use compressed saves for save in
2.3.0 and for save.image in 2.4.0. Any recent version of R
can read compressed save files, and a compressed file can be
uncompressed (by gzip -d) for use with very old versions of R.
x <- runif(20)
y <- list(a = 1, b = TRUE, c = "oops")
save(x, y, file = "xy.Rdata")
save.image()
unlink("xy.Rdata")
unlink(".RData")
# set save defaults using option:
options(save.defaults=list(ascii=TRUE, safe=FALSE))
save.image()
unlink(".RData")