Many thanks to all for resolving my issue!
On Thu, Aug 27, 2009 at 10:33 PM, Martin Maechler <
maech...@stat.math.ethz.ch> wrote:
> >>>>> "MO" == Moshe Olshansky <m_olshan...@yahoo.com>
> >>>>> on Wed, 26 Aug 2009 23:36:22 -0700 (PDT) writes:
>
> MO> You can do
> MO> for (i in 1:ncol(x)) {names <-
> rownames(x)[which(x[,i]==1)];eval(parse(text=paste("V",i,".ind<-names",sep="")));}
>
> you can, but after install.packages("fortunes")
>
> > require("fortunes")
> > fortune("parse")
>
> If the answer is parse() you should usually rethink the question.
> -- Thomas Lumley
> R-help (February 2005)
>
>
> So please use one of the other answers given in the thread...
>
>
> MO> --- On Thu, 27/8/09, Steven Kang <stochastick...@gmail.com> wrote:
>
> >> From: Steven Kang <stochastick...@gmail.com>
> >> Subject: [R] Help on efficiency/vectorization
> >> To: r-help@r-project.org
> >> Received: Thursday, 27 August, 2009, 4:13 PM
> >> Dear R users,
> >>
> >> I am trying to extract the rownames of a data set for which
> >> each columns
> >> meet a certain criteria. (condition - elements of each
> >> column to be equal
> >> 1)
> >>
> >> I have the correct result, however I am seeking for more
> >> efficient (desire
> >> vectorization) way in implementing such problem as it can
> >> get quite messy if
> >> there are hundreds of columns.
> >>
> >> Arbitrary data set and codes are shown below for your
> >> reference:
> >>
> >> x <- as.data.frame(matrix(round(runif(50),0),nrow=5))
> >>
> >> rownames(x) <- letters[1:dim(x)[1]]
> >>
> >> > x
> >> V1 V2 V3 V4 V5 V6 V7 V8 V9 V10
> >> a 0 1 1
> >> 1 0 0
> >> 0 0 1 0
> >> b 1 1 1
> >> 1 0 1
> >> 0 0 1 1
> >> c 0 1 1
> >> 0 0 0
> >> 0 0 0 1
> >> d 1 0 0
> >> 1 1 1
> >> 1 1 0 0
> >> e 1 0 0
> >> 0 0 1
> >> 1 0 1 0
> >>
> >> V1.ind <- rownames(x)[x[,"V1"]==1]
> >> V2.ind <- rownames(x)[x[,"V2"]==1]
> >> V3.ind <- rownames(x)[x[,"V3"]==1]
> >> V4.ind <- rownames(x)[x[,"V4"]==1]
> >> :
> >> :
> >> V10.ind <- rownames(x)[x[,"V10"]==1]
> >>
> >> > V1.ind
> >> [1] "b" "d" "e"
> >> > V2.ind
> >> [1] "a" "b" "c"
> >> > V3.ind
> >> [1] "a" "b" "c"
> >> :
> >> :
> >> > V10.ind
> >> [1] "b" "c"
> >>
> >>
> >>
> >> Your expertise in resolving this issue would be highly
> >> appreciated.
> >>
> >>
> >> Steve
> >>
> >> [[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<http://www.r-project.org/posting-guide.html>
> >> and provide commented, minimal, self-contained,
> >> reproducible code.
> >>
>
> MO> ______________________________________________
> MO> R-help@r-project.org mailing list
> MO> https://stat.ethz.ch/mailman/listinfo/r-help
> MO> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
> MO> and provide commented, minimal, self-contained, reproducible code.
>
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