> Note how S3 methods are dispatched only by reference to the first > argument (on the left of the operator). I think S4 beats this by > having signatures that can dispatch depending on both arguments.
That's somewhat of a simplification for primitive binary operators. R actually looks up the method for both input classes, and returns a error if they are different. Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
