Hi, related to this important discussion I have several questions:
What can I do to explicitly state that I want to use a certain, *non-exported* generic function? The function I am currently talking of is predict.smooth.spline from package stats. As I want to make shure that *this* function is used I currently call stats:::predict.smooth.spline() in my code, which now triggers a NOTE on CRAN. Strange enough predict.smooth.spline even has a manual page but is not exported (as is true for many other generic functions as well).
Is it advisable to specify (S3) methods without exporting them? How can I access exactly this function without using :::? And/or shouldn't we (R Core in this instance but others - including myself) export all methods (especially if a manual exists anyway)?
A related question concerns the function stats:::n.knots. I want to use this function to compute the number of knots for a spline (not necessarily a smoothing spline as defined by smooth.spline were it is originally used). The source of the function even states as a comment: "## Namespace-hidden but at least available to programmeRs:" So I guess this function can be considered to be stable and usable. Would it then be possible for R Core to export this function?
Finally, if one needs to copy a function (perhaps with minor modifications), how does one properly state the authorship of the code that one copies? Are there any guidelines, rules, ...? Is it sufficient for small functions to state the original authorship as a comment in the source? Is it necessary to state the authorship in the manual? Or is it even required to state the quthorship in the DESCRITPION? I already did an extensive search of the R-devel mailing list but couldn't find an appropriate answer. And after all I do not want to spend hours and hours thinking about licenses, authorship etc. but I want to produce nice and usable code (but also want to mention the original authors appropriately)!
Happy to learn more and read your thoughts and ideas about these issues. All the best, Benjamin ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
