[R] skipping columns in read.table; was: (no subject)

[Uwe Ligges]

On 02.08.2013 05:29, Babu Guha wrote:
> I have a comma delimited file with 62 fields of which some are comments.
> There are about 1.5 million records/lines. Sme of the fields which has
> comments and which i do not need have 40 characters. Of the 62 fields, I
> will need at most 12 fields. What's best way to read in the fields I need.
> If I read the entire file at once I will run out of memory. Could anyone
> please suggest some solution?

See ?read.table and its argument colClasses:

read.table(file, colClasses=c("numeric", "NULL", "factor"))

Will read the first column as a numeric one, skip the second column and 
take the thirs one as a factor.

Best,
Uwe Ligges


>
> Thanks,
> Babu.
>
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