Alfredo Alessandrini wrote: > Hi, > > With this data.frame: > > >> class(rwl) >> > [1] "data.frame" > > >> rwl >> > 0028002F 0028013F 0028032F > 1833 3.39 NA NA > 1834 3.09 NA NA > 1835 3.05 NA NA > 1836 3.31 NA NA > 1837 2.26 NA NA > > >> colnames(rwl) >> > [1] "0028002F" "0028013F" "0028032F" > > Ok.... > > >> colnames(rwl[,1]) >> > NULL > > why?? I expect: "0028002F" > > have you read the docs? start with ?`[`
you're yet another user confused by r's policy to drop dimensions as soon as possible. when you select one column from a data frame, you get a vector, not a one-column data frame. if you're always expecting a data frame while indexing, be sure to include 'drop=FALSE': > colnames(rwl[,1,drop=FALSE]) > [1] "0028002F" vQ ______________________________________________ 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.
