Thanks, Don!
Appreciated your detailed explanation.
On Thu, Sep 1, 2011 at 11:28 AM, MacQueen, Don <macque...@llnl.gov> wrote:
> Even though it's not needed, here's a small followup.
>
> I usually use this
> split(x, paste(x$let,x$g))
>
> But since
> split(x, list(x$let,x$g))
> works, so does
> split(x, x[,c('let','g')])
>
> > all.equal( split(x, x[,c('let','g')]) , split(x,list(x$let,x$g)))
> [1] TRUE
>
>
> As to which is the best, hard to say. If the variable names you want to
> split by are held in character vector, then the third one has an advantage
>
> splt.by <- c('let','g')
> split(x, x[,splt.by] )
>
> If x were large, and the number of columns to split by were large, there
> might be performance differences, but I suspect they would have to be
> *very* large before it mattered.
>
> -Don
>
>
> --
> Don MacQueen
>
> Lawrence Livermore National Laboratory
> 7000 East Ave., L-627
> Livermore, CA 94550
> 925-423-1062
>
>
>
>
>
> On 9/1/11 11:08 AM, "Changbin Du" <changb...@gmail.com> wrote:
>
> >Thanks for the great helps from David, Jim and Liviu. It solved my
> >problem.
> >
> >Appreciated!
> >
> >On Thu, Sep 1, 2011 at 11:01 AM, David Winsemius
> ><dwinsem...@comcast.net>wrote:
> >
> >>
> >> On Sep 1, 2011, at 1:53 PM, Changbin Du wrote:
> >>
> >> HI, Dear R community,
> >>>
> >>> I want to split a data frame by using two variables: let and g
> >>>
> >>> x = data.frame(num =
> >>>>
> >>> c(10,11,12,43,23,14,52,52,12,**23,21,23,32,31,24,45,56,56,76,**45),
> >>>let =
> >>> letters[1:5], g = 1:2)
> >>>
> >>>> x
> >>>>
> >>> num let g
> >>> 1 10 a 1
> >>> 2 11 b 2
> >>> 3 12 c 1
> >>> 4 43 d 2
> >>> 5 23 e 1
> >>> 6 14 a 2
> >>> 7 52 b 1
> >>> 8 52 c 2
> >>> 9 12 d 1
> >>> 10 23 e 2
> >>> 11 21 a 1
> >>> 12 23 b 2
> >>> 13 32 c 1
> >>> 14 31 d 2
> >>> 15 24 e 1
> >>> 16 45 a 2
> >>> 17 56 b 1
> >>> 18 56 c 2
> >>> 19 76 d 1
> >>> 20 45 e 2
> >>>
> >>> I tried the following:
> >>>
> >>> xs = split(x,x$g*x$let)
> >>>
> >>
> >> Probably
> >>
> >> xs = split(x,list(x$g,x$let))
> >>
> >>>
> >>> *Warning message:
> >>> In Ops.factor(x$g, x$let) : * not meaningful for factors*
> >>>
> >>>
> >>> xs = split(x,c(x$g*x$let))
> >>>
> >>> *Warning message:
> >>> In Ops.factor(x$g, x$let) : * not meaningful for factors
> >>> *
> >>>
> >>> Can someone give some hints?
> >>>
> >>> Thanks!
> >>>
> >>>
> >>> --
> >>> Sincerely,
> >>> Changbin
> >>> --
> >>>
> >>> [[alternative HTML version deleted]]
> >>>
> >>> ______________________________**________________
> >>> R-help@r-project.org mailing list
> >>>
> >>>https://stat.ethz.ch/mailman/**listinfo/r-help<
> https://stat.ethz.ch/mail
> >>>man/listinfo/r-help>
> >>> PLEASE do read the posting guide http://www.R-project.org/**
> >>> posting-guide.html <http://www.R-project.org/posting-guide.html>
> >>> and provide commented, minimal, self-contained, reproducible code.
> >>>
> >>
> >> David Winsemius, MD
> >> West Hartford, CT
> >>
> >>
> >
> >
> >--
> >Sincerely,
> >Changbin
> >--
> >
> >Changbin Du
> >Data Analysis Group, Affymetrix Inc
> >6550 Emeryville, CA, 94608
> >
> > [[alternative HTML version deleted]]
> >
> >______________________________________________
> >R-help@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.
>
>
--
Sincerely,
Changbin
--
Changbin Du
Data Analysis Group, Affymetrix Inc
6550 Emeryville, CA, 94608
[[alternative HTML version deleted]]
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