[R] R and file size

Prof Brian Ripley ripley at stats.ox.ac.uk
Mon Jan 13 08:58:03 CET 2003


On Mon, 13 Jan 2003, Patrick Connolly wrote:

> On Tue, 07-Jan-2003 at 10:52AM +0000, ripley at stats.ox.ac.uk wrote:
>
> |> On Mon, 6 Jan 2003, Greg Blevins wrote:
> |>
> |> > I will be involved with an analysis based on a file that will be roughly 25 meg.  Assuming I have enough memory, is their any limitations to using R on a file this large.
> |>
> |> That's a small file!
> |>
> |> Seriously, people work on datasets of 100Mb or so in 1Gb (or even 512Mb)
> |> machines.  However, some care is needed to select a good way to read the
> |> data in (if read.table, do follow the advice on the help page), and it
>
> My attention was drawn to said help page and noticed something rather
> odd.
>
> Usage:
>
>      read.table(file, header = FALSE, sep = "", quote = "\"'", dec = ".",
>                 row.names, col.names, as.is = FALSE, na.strings = "NA",
>                 colClasses = NA, nrows = -1,
>                 skip = 0, check.names = TRUE, fill = !blank.lines.skip,
>                 strip.white = FALSE, blank.lines.skip = TRUE,
>                 comment.char = "#")
>
> However, when I check out the function itself:
>
> > args(read.table)
> function (file, header = FALSE, sep = "", quote = "\"'", dec = ".",
>     row.names, col.names, as.is = FALSE, na.strings = "NA", skip = 0,
>     check.names = TRUE, fill = !blank.lines.skip, strip.white = FALSE,
>     blank.lines.skip = TRUE)

That is odd, as it should give

> args(read.table)
function (file, header = FALSE, sep = "", quote = "\"'", dec = ".",
    row.names, col.names, as.is = FALSE, na.strings = "NA", colClasses = NA,
    nrows = -1, skip = 0, check.names = TRUE, fill = !blank.lines.skip,
    strip.white = FALSE, blank.lines.skip = TRUE, comment.char = "#")
NULL

I think you have a very old private version masking the real one!

> Something simple, no doubt, but nothing I can see.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595




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