dput
Write an Object to a File or Recreate it
Writes an ASCII text representation of an R object to a file or connection, or uses one to recreate the object.
- Keywords
- file, programming, connection
Usage
dput(x, file = "",
control = c("keepNA", "keepInteger", "niceNames", "showAttributes"))dget(file, keep.source = FALSE)
Arguments
- x
an object.
- file
either a character string naming a file or a connection.
""indicates output to the console.- control
character vector indicating deparsing options. See
.deparseOptsfor their description.- keep.source
logical: should the source formatting be retained when parsing functions, if possible?
Details
dput opens file and deparses the object x into
that file. The object name is not written (unlike dump).
If x is a function the associated environment is stripped.
Hence scoping information can be lost.
Deparsing an object is difficult, and not always possible. With the
default control, dput() attempts to deparse in a way
that is readable, but for more complex or unusual objects (see
dump), not likely
to be parsed as identical to the original. Use control = "all"
for the most complete deparsing; use control = NULL for the
simplest deparsing, not even including attributes.
dput will warn if fewer characters were written to a file than
expected, which may indicate a full or corrupt file system.
To display saved source rather than deparsing the internal
representation include "useSource" in control. R
currently saves source only for function definitions. If you do not
care about source representation (e.g., for a data object), for speed
set options(keep.source = FALSE) when calling source.
Value
For dput, the first argument invisibly.
For dget, the object created.
Note
This is not a good way to transfer objects between R sessions.
dump is better, but the function save is
designed to be used for transporting R data, and will work with R
objects that dput does not handle correctly as well as being
much faster.
To avoid the risk of a source attribute out of sync with the actual function definition, the source attribute of a function will never be written as an attribute.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
See Also
Examples
library(base)
# NOT RUN {
fil <- tempfile()
## Write an ASCII version of the 'base' function mean() to our temp file, ..
dput(base::mean, fil)
## ... read it back into 'bar' and confirm it is the same
bar <- dget(fil)
stopifnot(all.equal(bar, base::mean))
## Create a function with comments
baz <- function(x) {
# Subtract from one
1-x
}
## and display it
dput(baz)
## and now display the saved source
dput(baz, control = "useSource")
## Numeric values:
xx <- pi^(1:3)
dput(xx)
dput(xx, control = "digits17")
dput(xx, control = "hexNumeric")
dput(xx, fil); dget(fil) - xx # slight rounding on all platforms
dput(xx, fil, control = "digits17")
dget(fil) - xx # slight rounding on some platforms
dput(xx, fil, control = "hexNumeric"); dget(fil) - xx
unlink(fil)
xn <- setNames(xx, paste0("pi^",1:3))
dput(xn) # nicer, now "niceNames" being part of default 'control'
dput(xn, control = "S_compat") # no names
## explicitly asking for output as in R < 3.5.0:
dput(xn, control = c("keepNA", "keepInteger", "showAttributes"))
# }