[R] reading only some columns from a table

[Gabor Grothendieck]

Sorry, here it is fixed up.  The c should have been list:


Lines <- "conid person construct
1 1 offence
2 1 insight"

read.table(textConnection(Lines), header = TRUE,
  colClasses = list(person = NULL))


On 10/30/06, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> Here is an example:
>
> > Lines <- "conid person construct
> + 1 1 offence
> + 2 1 insight"
> >
> > read.table(textConnection(Lines), header = TRUE,
> +   colClasses = c(person = NULL))
>  conid person construct
> 1     1      1   offence
> 2     2      1   insight
>
>
>
>
> On 10/30/06, Amir Safari <amsa36060 at yahoo.com> wrote:
> >
> >  Thank you so much for reply. I tried to do your suggested idea. It did not
> > work. what could be my mistake ? I got the same result with and without
> > colClasses=c() arguement. What could be the reason? even using header=TRUE
> > the result change slightly but not into desired one.
> >
> >
> >
> > Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> > See the colClasses argument of read.table.
> >
> > e.g.
> >
> > read.table("myfile", header = TRUE, colClasses = c(person = NULL))
> >
> > assuming you don't want the column labelled person in the header.
> >
> > On 10/30/06, Amir Safari wrote:
> > >
> > >
> > > Dear R users,
> > > Sometimes it is needed to read only some columns from a table, in
> > particulare for high frequency data. How it is possible to read just some
> > certain columns using read.table ( ). The reason could be keeping space in R
> > and in particular accelerating in reading data when the number of rows are
> > huge and some of them are not needed.
> > > Thank you very much,
> > > Amir
> > >
> > >
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