Write an Object to a File or Recreate it

Description

Writes an ASCII text representation of an R object to a file, the R console, or a connection, or uses one to recreate the object.

Usage

dput(x, file = "", control = c("keepNA", "keepInteger", "niceNames", "showAttributes")) dget(file, keep.source = FALSE) 

Arguments

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 functions save and saveRDS are 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

deparse, .deparseOpts, dump, write.

Examples

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, check.environment = FALSE)) ## 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"))