Suggested by Bob Muenchen.
How about implementing this when .variables is NA? Currently:
> ddply(iris, .variables = NA, identity)
Error in UseMethod("as.quoted") :
no applicable method for 'as.quoted' applied to an object of class "logical"
I suggest changing this to calling the function for each row. Then,
rowwise <- function(...) d_ply(.variables = NA, ...)
Would you review a pull request?
Hmmm, NA doesn't clearly say rowwise to me
Unfortunately, NULL is equivalent to the empty list, and anything else might be interpreted as columns. What would you suggest?
I'm suggesting the enhancement of d*ply because this might be the easiest path, involving the least amount of changes and new code. It's still possible to refactor the d*ply functions to provide a worker so that the interface of d*ply remains unchanged. Would that be preferable?
That's a good point. I'd review a pull request, but I'm spending more time on dplyr these days.
In dplyr, and it's too big to consider for plyr now.