Hi r-help-boun...@r-project.org napsal dne 13.06.2011 17:19:39: > Patrizio Frederic <frederic.patri...@gmail.com> > > On Mon, Jun 13, 2011 at 4:45 PM, Barry Rowlingson > <b.rowling...@lancaster.ac.uk> wrote: > > On Mon, Jun 13, 2011 at 11:06 AM, Aparna <aparna.sampat...@gmail.com> wrote: > >> Hi All > >> > >> I am new to R and I am not sure of how this should be done. I have a matrix of > >> 985x100 values and the class is data.frame. > > > > You don't have a 'matrix' in the R sense of the word. You seem to > > have a table of numbers which are stored in an object of class > > 'data.frame'. > > > > but you could have one: > > a <- data.frame(matrix(rnorm(100),10) # get some data > class(a) # check for its class > as.numeric(a) # whoops, won't work > > class(as.matrix(a)) # change class, and > as.numeric(as.matrix(a)) # bingo, it works
Which results in vector of numbers str(as.numeric(as.matrix(a))) num [1:100] 0.82 -1.339 1.397 0.673 -0.461 ... data frame is convenient list structure which can contain vectors of various nature (numeric, character, factor, logical, ...) and looks quite similar to Excel table. matrix is a vector with (2) dimensions but as it is a vector it can not consist from objects of different nature (class). Therefore you can have numeric or character matrix but not numeric and character columns in your matrix. and vector is vector (numeric, character, logical, ...) but again you can not mix items of different class in one vector. Regards Petr > > PF > > > -- > +----------------------------------------------------------------------- > | Patrizio Frederic, > | http://www.economia.unimore.it/frederic_patrizio/ > +----------------------------------------------------------------------- > > ______________________________________________ > 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. ______________________________________________ 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.
