On Thu, 28 Sep 2006, Hans-Peter wrote: > Hello, > > What's the best/recommended way to drop the dimension of a data.frame? > Probably "test[,,]" but I am not sure. I would prefer an explicit > function, but drop doesn't work with frames and I didn't find > something in the helpfiles/mailarchive.
The recommended way is not to do it. If as it appears you want to extract a single column, do so explicitly by e.g. if(length(test) == 1) test[[1]] else test Your as.matrix versions will not work with general columns. > > Example: > > test <- data.frame( x = 1:7 ) > > str( drop( test ) ) # still a data.frame > > str( test[,, drop = TRUE] ) # ok > str( test[,,] ) # ok <== IS THIS THE WAY TO DO IT? > str( as.integer( as.matrix( test ) ) ) # ok > > str( drop( as.matrix( test ) ) ) # ~ok, named integer > test2 <- test > attributes( test2 ) <- NULL > str( drop( as.matrix( test2 ) ) ) # ok > > > Thanks and best regards, > Hans-Peter > > PS: how could I lookup the code for subsetting a data.frame. I suppose > that it is in "data.frame.[" > > ______________________________________________ > [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.
