Sorting problem

?Adding

xtfrm.numeric <- function(x) {x}

would seem to add the case that people are looking for -- unless
there's something special that needs to be handled with NAs ???

Yes, that was what I was suggesting.  xtfrm currently converts NaN to
NA, but that does not seem to be necessary for it to meet its
specification of "producing a numeric vector which will sort in the
same order as 'x'", since sort treats NaNs the same as NAs.

        -s