R: Cloning ffdf objects

clone.ffdf {ff} | R Documentation

## 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))

      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()

[Package ff version 2.2-13 Index]