ff (version 2.2-14)

clone.ffdf: Cloning ffdf objects

Description

clone physically duplicates ffdf objects

Usage

# S3 method for 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)

Value

An object of type ffdf

Details

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

See Also

clone, ffdf

Examples

# NOT RUN {
  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()
# }