On 5/2/2008 2:52 PM, Alex Joyner wrote:
Duncan,
Thank you for your response. I actually am using colClasses, but the
first column is a character column, and the rest are numeric. Is there
any way to specify that all columns are numeric except for the first
one? I couldn't find this in the documentation. Also, I can't remove the
first column until I read the file in right?
If you set colClasses = c("NULL", rep("numeric", 199)) you should get
what you want.
Duncan Murdoch
Thanks again!
Alex
> Date: Fri, 2 May 2008 14:34:39 -0400
> From: [EMAIL PROTECTED]
> To: [EMAIL PROTECTED]
> CC: r-help@r-project.org
> Subject: Re: [R] Loading large files in R
>
> On 5/2/2008 2:13 PM, ajoyner wrote:
> > Hello,
> > I'm attempting to load a ~110 MB text file with ~500,000 rows and 200
> > columns using read.table . R hangs and seems to give up. Can anyone
tell me
> > an efficient way to load a file of this size?
>
> It will help a lot if you specify the column types (using the colClasses
> argument), so that R doesn't have to determine them from the data.
>
> It will also help if you've got lots of physical memory available for R;
> depending on the data, that could take several hundred MB of memory, and
> if the OS needs to use swap space to get it, you'll find it very slow.
> If you want to limit the memory footprint, don't read all of the data at
> once: specify some columns to be skipped (set their class to "NULL") or
> some rows (using skip and/or nrow).
>
> Duncan Murdoch
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