colnames on a data.frame with implicit row.names > df <- data.frame(x=1:6000000)
is slow > system.time(colnames(df)) [1] 21.655 0.327 21.987 0.000 0.000 > system.time(names(df)) [1] 0 0 0 0 0 because colnames calls dimnames calls row.names.data.frame calls as.character on the implicit row.names. -- Martin T. Morgan Bioconductor / Computational Biology http://bioconductor.org ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
