ff: as.ffdf – R documentation

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as.ffdf

Coercing to ffdf and data.frame

Description

Functions for coercing to ffdf and data.frame

Usage

as.ffdf(x, ...)
## S3 method for class 'ff_vector'
as.ffdf(x, ...)
## S3 method for class 'ff_matrix'
as.ffdf(x, ...)
## S3 method for class 'data.frame'
as.ffdf(x, vmode=NULL, col_args = list(), ...)
## S3 method for class 'ffdf'
as.data.frame(x, ...)

Arguments

`x`	the object to be coerced
`vmode`	optional specification of the `vmodes` of columns of the `data.frame`. Either a character vector of vmodes (named with column names of the data.frame or recycled if not named) or a list named with vmodes where each element identifies those columns of the data.frame that should get the vmode encoded in the name of the element
`col_args`	further arguments; passed to `ff`
`...`	further arguments; passed to `ffdf` for .ff_vector, .ff_matrix and .data.frame methods, ignored for .ffdf identity method

Value

'as.ffdf' returns an object of class ffdf, 'as.data.frame' returns an object of class data.frame

Author(s)

Jens Oehlschlägel

Examples

d <- data.frame(x=1:26, y=letters, z=Sys.time()+1:26, stringsAsFactors = TRUE)
  ffd <- as.ffdf(d)
  stopifnot(identical(d, as.data.frame(ffd)))
  rm(ffd); gc()

ff

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

v4.0.4

GPL-2 | GPL-3 | file LICENSE

Authors

Daniel Adler [aut], Christian Gläser [aut], Oleg Nenadic [aut], Jens Oehlschlägel [aut, cre], Martijn Schuemie [aut], Walter Zucchini [aut]

Initial release

2020-10-13