ff (version 4.5.0)

vt: Virtual transpose

Description

The vt generic does a matrix or array transpose by modifying virtual attributes rather than by physically copying matrix elements.

Usage

vt(x, ...)
# S3 method for ff
vt(x, ...)
# S3 method for default
vt(x, ...)
# S3 method for ff
t(x)

Value

an object that behaves like a transposed matrix

Arguments

x

an ff or ram object

...

further arguments (not used)

Author

Jens Oehlschlägel

Details

The vt.ff method does transpose through reversing dim.ff and dimorder. The vt.default method is a wrapper to the standard transpose t.
The t.ff method creates a transposed clone.
If x has a virtual window vw defined, vt.ff returns an ff object with a transposed virtual window, the t.ff method return a transposed clone of the virtual window content only.

See Also

dim.ff, vw, virtual

Examples

  x <- ff(1:20, dim=c(4,5))
  x
  vt(x)
  y <- t(x)
  y
  vw(x) <- cbind(c(1,3,0),c(1,4,0))
  x
  vt(x)
  y <- t(x)
  y
  rm(x,y); gc()