Full_Name: Ulrike Groemping Version: 2.9.0 OS: Windows Submission from: (NULL) (84.190.173.190)
The documentation for data.frame contains the sentence "A data frame is a list of variables of the same length with unique row names, given class "data.frame"." This of course does describe the standard use of data frames, but other versions are possible (e.g. df <- swiss; df$proof <- as.matrix(swiss); ncol(df); df; length(df$proof)), which is important to know at least for package developers and should be documented (it is documented with the extractor methods for data.frame, but I don't think that this is sufficient). Regards, Ulrike ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
