[R] R and file size

[Patrick Connolly]

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) 



Consequently, I can't set nrows to see if it would be an improvement.

> version
         _                
platform i686-pc-linux-gnu
arch     i686             
os       linux-gnu        
system   i686, linux-gnu  
status                    
major    1                
minor    6.1              
year     2002             
month    11               
day      01               
language R   


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

Ideas welcome.


-- 
Patrick Connolly
HortResearch
Mt Albert
Auckland
New Zealand 
Ph: +64-9 815 4200 x 7188
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