On Wed, 7 Dec 2005, Kurt Wollenberg wrote: > Greetings all: > > OK, this is bugging the @[EMAIL PROTECTED] out of me. I know the answer is > simple > and straightforward but for the life of me I cannot find it in the > documentation, in the archives, or in my notes (because I know I've > encountered this in the past). My problem is: > > I have a data frame with columns A, B, C, D, and E. A, B, and E are > factors and C and D are numeric. I need a new data frame with just A, > C, and D. When I copy these columns to a new data frame > > >newDF <- data.frame(cbind(oldDF$A, oldDF$C, oldDF$D))
set.seed(1) oldDF <- data.frame(A=rnorm(5), B=rnorm(5), C=factor(letters[1:5]), D=rnorm(5)) str(oldDF) newDF <- data.frame(cbind(oldDF$A, oldDF$C, oldDF$D)) str(newDF) # cbind forces to numeric as a matrix, so avoid it here newDFa <- data.frame(Aa=oldDF$A, Ca=oldDF$C, Da=oldDF$D) str(newDFa) > > all the factor data comes out as levels rather than the original > factors. How do I preserve the factors when I copy from one data frame > to another? > > > Thanks vary much, > Kurt Wollenberg, Ph.D. > Tufts Center for Vision Research > Tufts-New England Medical Center > 750 Washington St #450 > Boston, MA 02111 > Office: 617-636-9028 > Fax: 617-636-8945 > email: kurt.wollenberg at gmail dot com > > ______________________________________________ > 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 > -- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: [EMAIL PROTECTED] ______________________________________________ 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
