Tim Triche, Jr. <tim.triche <at> gmail.com> writes: > a n00b question: > > if I call importFrom(IRanges, ranges) in my NAMESPACE file, that works > great. > but if I call > > R> importFrom(IRanges, ranges) > ## Error: could not find function "importFrom" > > well, that doesn't work great. The closest thing I can find in base is > > base:::importIntoEnv > > which helpfully informs me that it is one of several > > Internal namespace support functions. Not intended to be called directly. > > Where's the best place to learn about how namespaces and import/export > facilities (particularly in R-3.0) are implemented?
Have you tried the R Extensions manual? That doesn't quite answer the "how are they implemented" question, but it should cover "how should they be used" about as thoroughly as possible. http://obeautifulcode.com/R/How-R-Searches-And-Finds-Stuff/ may be useful as well. Beyond that, you have to look at the R language manual (if at has anything) or the source code, I think. > On Sun, Jan 13, 2013 at 7:05 AM, Dirk Eddelbuettel <edd <at> debian.org> > wrote: > > > > > On 13 January 2013 at 11:16, Johannes Graumann wrote: > > | In a little pkg I'm developing I am in need of the functionality > > provided by > > | plotrix::listDepth. > > | > > | I am loath of having the depend on and import the whole package just for > > | that purpose. > > > > Step back and realize that your total R installation (including all > > packages) > > is already much bigger than the single package. And derives value from all > > those packages. > > > > So I would use importForm(plotrix, listDepth) in my package's NAMESPACE, > > and > > add the Imports: in the DESCRIPTION. > > > > IMHO that is the right way to do it rather than creating _stale_ and (even > > worse) _disconnected_ copies which will never receive updates or fixes from > > the _original author_ of that code. > > > > Dirk I agree/sympathize but can also think of cases, if the function is short/simple enough, that it would actually make sense to copy it. It's a judgment call, I think. Most R packages are under sufficiently permissive licenses (plotrix is 'GPL >=2') that copying is allowed, although it would be courteous to inform/ask permission from the author(s). Ben Bolker ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
