Getting and setting names

For ff_vectors you can set names, though this is not recommended for large objects.

# S3 method for class 'ff'
names(x)
  # S3 method for class 'ff'
names(x) <- value
  # S3 method for class 'ff_array'
names(x)
  # S3 method for class 'ff_array'
names(x) <- value

Arguments

x

a ff vector

value

a character vector

Details

If vw is set, names.ff returns the appropriate part of the names, but you can't set names while vw is set. names.ff_array returns NULL and setting names for ff_arrays is not allowed, but setting dimnames is.

Value

names returns a character vector (or NULL)

Author

Jens Oehlschlägel

See also

names, dimnames.ff_array, vw, virtual

Examples

  x <- ff(1:26, names=letters)
  names(x)
#>  [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s"
#> [20] "t" "u" "v" "w" "x" "y" "z"
  names(x) <- LETTERS
  names(x)
#>  [1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S"
#> [20] "T" "U" "V" "W" "X" "Y" "Z"
  names(x) <- NULL
  names(x)
#> NULL
  rm(x); gc()
#>           used (Mb) gc trigger  (Mb) max used  (Mb)
#> Ncells 1161864 62.1    1994352 106.6  1994352 106.6
#> Vcells 2165349 16.6    8790397  67.1  8790397  67.1