[Rd] Including modified R source code in a package

[Duncan Murdoch]

On 13-02-18 4:33 PM, Hadley Wickham wrote:
> Hi all,
>
> I would like to include a function that I have made by modifying an
> existing R function (bw.SJ and corresponding code in bandwidths.c).
> The header of bandwidths.c states:
>
> /*
>   *  R : A Computer Language for Statistical Data Analysis
>   *  bandwidth.c by W. N. Venables and B. D. Ripley  Copyright (C) 1994-2001
>   *  Copyright (C) 2012  The R Core Team
>   *
>   *  This program is free software; you can redistribute it and/or modify
>   *  it under the terms of the GNU General Public License as published by
>   *  the Free Software Foundation; either version 2 of the License, or
>   *  (at your option) any later version.
>   ...
> */
>
> so it was originally written by Bill Venables and Brian Ripley, who in
> 2012 passed the copyrights to the R core team.

I would not assume that:  I would assume that the R Core Team licensed 
the source from Venables and Ripley (maybe under the GPL, but not 
necessarily), and both them and R Core Team now hold copyright, and are 
willing to license it to you under the GPL.

>
> What do I need to do to ensure meet my obligations under the GPL and

I won't give legal advice.

> to adequately acknowledge the work of the original authors.
> Currently:
>
> * my package has a compatible license (also GPL >= 2), and
>
> * I have acknowledged the authors in the documentation for my function
>
> * In the code, I have retained the copyrights of the original authors
>
> Do I also need to include Brian, Bill or the R core team in the
> authors at R field in my DESCRIPTION (as contributors)?

That seems reasonable.

Duncan Murdoch