as.ffdf: Coercing to ffdf and data.frame

In kindlychung/ff: memory-efficient storage of large data on disk and fast access functions

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 Oehlschl<c3><a4>gel

See Also

is.ffdf, ffdf, data.frame

Examples

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

kindlychung/ff documentation built on May 20, 2019, 9:58 a.m.