[Rd] Bug report - duplicate row names with as.data.frame()

Martyn Plummer plummerm at iarc.fr
Thu Mar 1 18:23:04 CET 2018

On Thu, 2018-03-01 at 09:36 -0500, Ron wrote:
> Hello,
> I'd like to report what I think is a bug: using as.data.frame() we can
> create duplicate row names in a data frame. R version 3.4.3 (current stable
> release).
> Rather than paste code in an email, please see the example formatted code
> here:
> https://stackoverflow.com/questions/49031523/duplicate-row-names-in-r-using-as-data-frame
> I posted to StackOverflow, and consensus was that we should proceed with
> this as a bug report.

Yes that is definitely a bug. 

The end of the as.data.frame.matrix method has:

    attr(value, "row.names") <- row.names
    class(value) <- "data.frame"

Changing this to:

    class(value) <- "data.frame"
    row.names(value) <- row.names

ensures that the row.names<-.data.frame method is called with its built
-in check for duplicate names.

There are quite a few as.data.frame methods so this could be a
recurring problem. I will check.


> Thanks,
> Ron
> 	[[alternative HTML version deleted]]
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

More information about the R-devel mailing list