[datatable-help] Need help with fread function

[Matthew Dowle]

Hi,

There seems to be a printing problem in that error message (-0.0MB 
should say 2.5GB), but other than that I can't think of much else to add 
that isn't in the error message already. The error message tells us you 
are using a 32bit computer. Are you Windows or Linux?  2.5GB is over 
2^31 bits, so at the limit of addressability for 32bit.  The file 
doesn't need to fit in RAM, but it does need to be addressable.  For 
example if you had 1GB of RAM, you should be able to read a 1.5GB file 
ok. It's not the amount of RAM you have per se, but whether you are 
32bit or 64bit.

Matthew


On 02.04.2013 05:06, vishal wrote:
> I am trying to read 2.5GB pipe delimited text file in R using fread 
> but I am
> getting below error.
>
> "  Opened file ok, obtained its size on disk (-0.0MB), but couldn't 
> memory
> map it. This is a 32bit machine. You don't need more RAM per se but 
> this
> fread function is tuned for 64bit addressability, at the expense of 
> large
> file support on 32bit machines. You probably need more RAM to store 
> the
> resulting data.table, anyway. And most speed benefits of data.table 
> are on
> 64bit with large RAM, too. Please either upgrade to 64bit (e.g. a 
> 64bit
> netbook with 4GB RAM can cost just £300), or make a case for 32bit 
> large
> file support to datatable-help."
>
> I have used following syntax.
> setwd("E:/Projects/Alo")
> library(data.table)
> f <- fread("6.txt",header="auto")
>
>
>
> --
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