On Wed, 27 Jun 2001 P.J.Wells@open.ac.uk wrote:
> The following is from the Help file on these functions:
>
> "...The na.omit and na.exclude functions return the same data frame.
> However, na.exclude adds extra information on which rows were removed as the
> na.action attribute of the data frame. ..."
What version is that? On the current S-PLUS 6.0 it says
`na.exclude' differs from `na.omit' only in the class of the
`"na.action"' attribute of the result, which is `"exclude"'. This
gives different behaviour in functions making use of `naresid' and
`napredict': when `na.exclude' is used the residuals and
predictions are padded to the correct length by inserting `NA's
for cases omitted by `na.exclude'.
> I do
>
> test.exclude <- na.exclude(my.data)
> test.omit <- na.omit(my.data)
>
> and then
>
> > names(attributes(test.exclude))
> [1] "names" "na.action" "class" "row.names"
>
> > names(attributes(test.omit))
> [1] "names" "na.message" "na.action" "class" "row.names"
>
> >From reading the Help I had expected fewer attributes from na.omit, not
> more.
>
> Am I missing something?
The above quote should help.
--
Brian D. Ripley, ripley@stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595
|