[Rd] Including modified R source code in a package

[Hadley Wickham]

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.

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

Is there anything else I should do?

Thanks!

Hadley

-- 
Chief Scientist, RStudio
http://had.co.nz/