[R] Reading large files in R

[Adaikalavan Ramasamy]

>From Note section of help("read.delim") :

     'read.table' is not the right tool for reading large matrices,
     especially those with many columns: it is designed to read _data
     frames_ which may have columns of very different classes. Use
     'scan' instead.

So I am not sure why you used 'scan', then converted it to a data frame.

1) Can provide an sample of the data that you are trying to read in.
2) How much memory does your machine has ?
3) Try reading in the first few lines using the nmax argument in scan.

Regards, Adai



On Mon, 2005-08-08 at 12:50 -0600, Jean-Pierre Gattuso wrote:
> Dear R-listers:
> 
> I am trying to work with a big (262 Mb) file but apparently reach a  
> memory limit using R on a MacOSX as well as on a unix machine.
> 
> This is the script:
> 
>  > type=list(a=0,b=0,c=0)
>  > tmp <- scan(file="coastal_gebco_sandS_blend.txt", what=type,  
> sep="\t", quote="\"", dec=".", skip=1, na.strings="-99", nmax=13669628)
> Read 13669627 records
>  > gebco <- data.frame(tmp)
> Error: cannot allocate vector of size 106793 Kb
> 
> 
> Even tmp does not seem right:
> 
>  > summary(tmp)
> Error: recursive default argument reference
> 
> 
> Do you have any suggestion?
> 
> Thanks,
> Jean-Pierre Gattuso
> 
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