Hi, Use Newdata <- subset(d2004, select=-c(concentration,stade))
See ?subset for details Best, Matthias > -----Ursprüngliche Nachricht----- > Von: Jacques VESLOT [mailto:[EMAIL PROTECTED] > Gesendet: Donnerstag, 09. September 2004 12:38 > An: [EMAIL PROTECTED] > Betreff: [R] Indexing dataframe > > > I am sorry to ask such question, but I can't find a solution... > > I have a dataframe 'd2004' and I want to remove two columns: > 'd2004$concentration' and 'd2004$stade". > > I could do it just as follows: > > > names(d2004) > > [1] "Localite" "Date" "parcelle" "maille" > "presence.plant" "concentration" "stade.culture" > [8] "stade" "Trou" "Horizon" "Profondeur" > > > d2004 <- d2004[, -c(6, 8)] > > but I'd like to use column names (to avoid finding column > numbers each time). > > I cannot find an easy way to operate... > > I wonder why that works: > > d2004[, "concentration"] > > and this don't: > > d2004 <- d2004[, -c("concentration", "stade")] > > Thanks... > > Jacques VESLOT / CIRAD > > ______________________________________________ > [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 > ______________________________________________ [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