Re: [R] Skipping columns to save memory

From: Duncan Murdoch <>
Date: Fri, 30 May 2008 09:25:01 -0400

On 5/30/2008 8:54 AM, Doran, Harold wrote:
> I have a very large tab delimited file (~ 1.97 GB) that I need to read
> in to R. The data contain 10 columns and there are millions of rows.
> I need all rows of the data, but I only need the first column in the
> data. I was looking at the ?read.delim and am trying to see if it is
> possible to tell this function only to read in the first column and skip
> the others.
> The help file says the number of columns are determined from the first 5
> rows of the data. So, I think one (very bad) option is to go into the
> text file and manually delete columns 2:10 for the first 5 rows only.
> Then, I think read.delim would think there is only 1 column in the data.
> The skip function is of course only for rows AFAIK.
>'skip columns read.delim')
> Or'skip columns') didn't return anything.
> Are there arguments in this function I have misunderstood or, are other
> functions better for this problem?

If an entry in colClasses is set to "NULL", then that column is skipped.

Duncan Murdoch mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Mon 02 Jun 2008 - 05:22:20 GMT

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