luke at stat.uiowa.edu
Tue Apr 1 21:45:16 MEST 2003
On Tue, 1 Apr 2003, Luke Tierney wrote:
> On Tue, 1 Apr 2003, John Chambers wrote:
> > I think this is a consequence of the extra context added to make methods
> > work right with R lexical scoping, namespaces, etc. Or a subtlety in
> > R's definition of missing()?
> > The problem is that somehow the default expression for argument `ncol'
> > makes that argument appear NOT to be missing. But an attempt to
> > evaluate it fails because the local variable `n' hasn't been defined
> > yet.
> > The following debugging snippets, using trace on the method for
> > "numeric", show what's happening. But as to why, we need some expert
> > help! (Luke?)
> We need a bit more info transferred across from the generic and we
> need to reset the environments of the promises for missing arguments.
> I'll look into it.
A workaround should be in place in R-devel now.
University of Iowa Phone: 319-335-3386
Department of Statistics and Fax: 319-335-3017
241 Schaeffer Hall email: luke at stat.uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
More information about the R-devel