On Sat, 8 Dec 2007, Jay Emerson wrote: > We are building a package, and want to create S4 methods for both head and > mean for our own BigMatrix class. Following the recommendation in "Writing > R Extensions" we use exportMethods instead of export in NAMESPACE (this is > described as being "clearer"). This works for head, but not for mean. > Obviously we importFrom(utils, head), but don't need to do this for mean, > which is imported automatically from base.
And what is the error message? > If we export(mean) rather than exportMethods(mean), it works as intended. > A similar problem arises for a new generic function and an associated > method, colmean, where the use of exportMethods(colmean) fails, but > export(colmean) succeeds. > > We can build and use the package by using export instead of exportMethods, > but we suspect that we're missing something that might be important to > understand. > > Any hints or links to something we missed would be appreciated. I know there are problems if you define a generic and no methods in a package (that is what stats4 does for AIC), but it doesn't sound as if that is what you are doing. (Since the introduction of implicit generics - which may well apply to your mean() - it is possible to define a generic in a package without any methods stored there, not even a default method.) I saw nothing in your description that is different from several other pacakges. Without either the error messages or an example, we are reduced to guessing. Can you make a minimal version available to us to look at? -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
