clone.ffdf: Cloning ffdf objects

In ff: Memory-Efficient Storage of Large Data on Disk and Fast Access Functions

Cloning ffdf objects

Description

clone physically duplicates ffdf objects

Usage

## S3 method for class 'ffdf'
clone(x, nrow=NULL, ...)

Arguments

x	an ffdf
nrow	optionally the desired number of rows in the new object. Currently this works only together with initdata=NULL
...	further arguments passed to clone (usually not usefull)

Details

Creates a deep copy of an ffdf object by cloning all physical components including the row.names

Value

An object of type ffdf

Author(s)

Jens Oehlschlägel

See Also

clone, ffdf

Examples

  x <- as.ffdf(data.frame(a=1:26, b=letters, stringsAsFactors = TRUE))

  message("Here we change the content of both x and y by reference")
  y <- x
  x$a[1] <- -1
  y$a[1]

  message("Here we change the content only of x because y is a deep copy")
  y <- clone(x)
  x$a[2] <- -2
  y$a[2]
  rm(x, y); gc()

ff documentation built on Sept. 30, 2024, 9:38 a.m.