zave: Serialize one or more R objects to a zip archive

In omegahat/Rcompression: In-memory decompression for GNU zip and bzip2 formats

Serialize one or more R objects to a zip archive

Description

This is an alternative to the save function in R that saves a collection of R variables to a single archive file but maintains them in seperate "files" within the archive and allows them to be restored as a group or individually. Additionally, one can readily determine the names of the variables in the archive using names. There is an optional table of contents that allows us to determine the class and size of each object.

This format can be extended to know how to "jump" directly to a variable and so provide quick access to individual elements.

Usage

zave(..., list = character(), file = stop("Must specify file name"), 
      envir = parent.frame(), compression_level = 9, .addToc = TRUE, 
       append = FALSE)

Arguments

...	the objects to be serialized, specified by expression or variable name. These values can also be given as name = val and the name is used as the name in the resulting archive
list	like save, this is a way of specifying the variables to serialize by explicit variable name.
file	the name of the file to create or append to
envir	where to find the variables specified by name via list.
compression_level	the level of compression to use for the zip file. See zip.
.addToc	a logical value indicating whether to compute and add a table of contents data frame to the archive. This is a data frame containing the class and object size of the elements.
append	a logical value passed to zip

Value

An object of class RdzArchive-class or an error.

Author(s)

Duncan Temple Lang

See Also

load zip serialize save

Examples

 x = 1:10
 y = letters
 bob = zave(x, y, mtcars, other = x, file = "/tmp/bob.zip", bobo = 1:10, zz = 2 * log(1:100), oo = rnorm(10))
 names(bob)
 bob$.toc
 bob[["y"]]
 bob$oo
 bob[]
 load(bob)  # put them into the global environment


  # Appending to a previously created Rdz file.
 a = zave(mtcars, file = "bob.Rdz", append = FALSE)
 a$x = 1:10


  # Dealing with duplicates
  # Now that we have replace = TRUE, a$x replaces the existing x by default.
 a = zave(mtcars, file = "bob.Rdz", append = FALSE)
 a[["x"]] = 1:10
 a[["x", replace = FALSE]] = letters
 a[["x", replace = FALSE]] = 20

 a[["x"]]
 a[["x", last = FALSE]] # first x
 a[[4]]  # 2nd x, index includes .toc


 a = zave(list = list(mtcars = mtcars, x = 1:10, x = letters, x = 20),  file = "bob.Rdz", append = FALSE)
 a[["x"]]
 a[["x", last = FALSE]]
 a[[4]]  # 2nd x, index includes .toc

omegahat/Rcompression documentation built on Nov. 29, 2023, 12:45 a.m.