[R] combine two dataframe
Gabor Grothendieck
ggrothendieck at gmail.com
Wed Nov 14 13:45:46 CET 2007
On Nov 14, 2007 4:59 AM, sun <flyhyena at yahoo.com.cn> wrote:
> Thanks all for the answers. Both Merge and sqldf works perfectly for me.
> Well, I feel sqldf run a littile bit slower. And I failed to install this
> package (sqldf ) on my linux box.
Have never heard of anyone not being able to install sqldf on Linux
before. sqldf
is written in 100% R so it should run on all platforms R runs on and for
which its dependencies work, mainly RSQLite (or RMySQL). As mentioned on the
home page, http://sqldf.googlecode.com, sqldf is optimized for convenience,
not speed, so I would not think it would be the fastest.
>
> Denver, your approach also works, but in my case, data frame A has much more
> rows then B, so B has to be duplicated many many times.
>
> kind regards,
> Sun
>
>
> ----- Original Message -----
> From: "Gabor Grothendieck" <ggrothendieck at gmail.com>
> To: "sun" <flyhyena at yahoo.com.cn>
> Cc: <r-help at stat.math.ethz.ch>
> Sent: Tuesday, November 13, 2007 6:07 PM
> Subject: Re: [R] combine two dataframe
>
>
> > Try this:
> >
> >> A <- data.frame(a1 = c(1, 2, 1), a2 = c(2, 3, 3), a3 = c(3, 1, 2))
> >> B <- data.frame(b1 = 1:2, b2 = 2:1)
> >>
> >> library(sqldf)
> >> sqldf("select * from A, B")
> > a1 a2 a3 b1 b2
> > 1 1 2 3 1 2
> > 2 1 2 3 2 1
> > 3 2 3 1 1 2
> > 4 2 3 1 2 1
> > 5 1 3 2 1 2
> > 6 1 3 2 2 1
> >
> >
> > On Nov 13, 2007 6:49 AM, sun <flyhyena at yahoo.com.cn> wrote:
> >> I have two data frame A and B adn want to cross them.
> >> A has format as:
> >>
> >> a1 a2 a3
> >> 1 2 3
> >> 2 3 1
> >> 1 3 2
> >> ...
> >>
> >> B:
> >>
> >> b1 b2
> >> 1 2
> >> 2 1
> >> ...
> >>
> >> the combine result shall be something like
> >>
> >> a1 a2 a3 b1 b2
> >> 1 2 3 1 2
> >> 1 2 3 2 1
> >> 2 3 1 1 2
> >> 2 3 1 2 1
> >> 1 3 2 1 2
> >> 1 3 2 2 1
> >> ....
> >>
> >>
> >> is there a function able of doing this instead of loops?
> >>
> >> Thanks,
> >> Sun
> >>
> >> ______________________________________________
> >> R-help at r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide
> >> http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
> >>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
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