El mié, 04-10-2006 a las 09:52 -0400, John Chambers escribió:
> I think the problem in your case comes from the mechanism used to handle
> non-standard argument lists; notice that you have added 3 new
> arguments.
Yes, our object is always 5 dimensional. We could use (...) but it
looked overly complex.
> If you look at the body of the resulting method you will see
> that the mechanism used to handle this (defining a function .local)
> fails to copy the default value from the method, as in the simpler
> example below:
>
> > setMethod("[", c("mm"), function(x, i, j, k..., drop=FALSE)browser())
> [1] "["
> > selectMethod("[", "mm")
> Method Definition:
>
> function (x, i, j, ..., drop = TRUE)
> {
> .local <- function (x, i, j, k..., drop = FALSE)
> browser()
> .local(x, i, j, ..., drop = drop)
> }
>
>
> We can probably fix this. Meanwhile, the workaround is to use the same
> mechanism yourself, but get the default value right. Define your
> method as a function (like the .local you see when printing the current
> method) and then define a method with the formally correct arguments
> (function(x, i, j, ..., drop=FALSE)) and call your function from that
> method.
OK, many thanks.
> Beware there is _another_ related "bug": if you use callNextMethod(),
> it does not seem to copy the default value of drop= either. (It's a bit
> more debatable what callNextMethod() with no arguments should do in this
> case, so the problem here may be an "undesired feature" rather than a
> bug.) You didn't show your real method, so this may not apply in your
> example.
I am adding the whole method below, but I do not thing this applies as
it is currently written.
> By the way, I would be a little surprised if this had anything to do
> with changes in 2.4.0, at least those I'm aware of.
This maybe the case, but it was working fine in 2.3.1.
Cheers,
Iago
setMethod("[", signature(x="FLQuant"),
function(x, i="missing", j="missing", k="missing", l="missing",
m="missing",
..., drop=FALSE) {
if (missing(i))
#i <- dimnames(x at .Data)[1][[1]]
i <- seq(1, length(dimnames(x at .Data)[1][[1]]))
if (missing(j))
j <- dimnames(x at .Data)[2][[1]]
if (missing(k))
k <- dimnames(x at .Data)[3][[1]]
if (missing(l))
l <- dimnames(x at .Data)[4][[1]]
if (missing(m))
m <- dimnames(x at .Data)[5][[1]]
if (!drop) {
flq <- FLQuant(x at .Data[i, j, k, l, m, drop=FALSE])
units(flq) <- units(x)
quant(flq) <- quant(x)
}
else if(drop)
flq <- x at .Data[i, j, k, l, m, ..., drop=TRUE]
return(flq)
}
)
> Iago Mosqueira wrote:
> > Dear all,
> >
> > After installing R 2.4.0, a definition of "[" for an S4 class has
> > stopped working as the default for drop in the generic, TRUE, appears to
> > override the default in the method
> >
> > The method is defined for demonstration purposes as
> >
> > setMethod("[", signature(x="FLQuant"),
> > function(x, i="missing", j="missing", k="missing", l="missing",
> > m="missing", ..., drop=FALSE) {
> >
> > print(drop)
> > }
> > )
> >
> > When called as
> >
> > new('FLQuant')[1,]
> >
> > drop is TRUE, instead of FALSE. Am I missing something? Has there been a
> > change in R 2.4.0 of relevance here? I could not find it in the NEWS
> > file.
> >
> > Many thanks,
> >
> >
> > Iago Mosqueira
> >
> > ______________________________________________
> > R-devel at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> >
> >