I did not know the fact. Thanks for useful information.
On 1/24/07, Prof Brian Ripley <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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]] > >> > >> ______________________________________________ > >> [email protected] 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. > >> > > > > ______________________________________________ > > [email protected] 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, [EMAIL PROTECTED] > 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 > ______________________________________________ [email protected] 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.
