Re: [R] how to change the dataframe labels' ?

From: talepanda <talepanda_at_gmail.com>
Date: Wed 24 Jan 2007 - 13:43:43 GMT

I did not know the fact.
Thanks for useful information.

On 1/24/07, Prof Brian Ripley <ripley@stats.ox.ac.uk> wrote:
> Sorry, no: row.names<-() is what you want.
>
> rownames for matrices (and arrays)
> row.names for data frames.
>
> Using them the other way round usually works but can be very inefficient.
> From R-devel (where the worst inefficiencies are circumvented)
>
> The extractor functions try to do something sensible for any
> matrix-like object 'x'. If the object has 'dimnames' the first
> component is used as the row names, and the second component (if
> any) is used for the column names. For a data frame, 'rownames'
> and 'colnames' are calls to 'row.names' and 'names' respectively,
> but the latter are preferred.
>
>
> On Wed, 24 Jan 2007, talepanda wrote:
>
> > rownames()<- is what you want.
> >
> >> dat<-data.frame(V1=sample(10),V2=sample(10))
> >> dat
> > V1 V2
> > 1 2 5
> > 2 3 8
> > 3 8 4
> > 4 9 6
> > 5 6 2
> > 6 5 7
> > 7 10 3
> > 8 4 9
> > 9 1 10
> > 10 7 1
> >> dat<-dat[order(dat$V2),]
> >> dat
> > V1 V2
> > 10 7 1
> > 5 6 2
> > 7 10 3
> > 3 8 4
> > 1 2 5
> > 4 9 6
> > 6 5 7
> > 2 3 8
> > 8 4 9
> > 9 1 10
> >> rownames(dat)<-1:dim(dat)[1]
> > ## or rownames(dat)<-dat$V2
> >> dat
> > V1 V2
> > 1 7 1
> > 2 6 2
> > 3 10 3
> > 4 8 4
> > 5 2 5
> > 6 9 6
> > 7 5 7
> > 8 3 8
> > 9 4 9
> > 10 1 10
> >
> > HTH
> >
> > On 1/24/07, domenico pestalozzi <statadat@gmail.com> wrote:
> >> I import a dataframe composed by 2 variables and 14000 cases. Now I need
> the
> >> labels of the cases sorted by the second variable V2, but if I sort the
> >> dataframe according to the second variable:
> >>
> >> mydataframe<- mydataframe[order(mydataframe$V2),]
> >>
> >> I notice that the labels are always the same (that is, not ordered by
> V2).
> >>
> >> How to change them?
> >> I tried :
> >>
> >> labels(mydataframe)<-1:14000
> >>
> >> but it doesn't work.
> >>
> >> Thanks
> >>
> >> domenico
> >>
> >> [[alternative HTML version deleted]]
> >>
> >> ______________________________________________
> >> R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.
> >
>
> --
> Brian D. Ripley, ripley@stats.ox.ac.uk
> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
> University of Oxford, Tel: +44 1865 272861 (self)
> 1 South Parks Road, +44 1865 272866 (PA)
> Oxford OX1 3TG, UK Fax: +44 1865 272595
>



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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. Received on Thu Jan 25 14:46:04 2007

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