[R] dumping/loading objects with 'tsp' attribute

[Antonio, Fabio Di Narzo]

2006/11/23, Prof Brian Ripley <ripley a stats.ox.ac.uk>:
> On Thu, 23 Nov 2006, Antonio, Fabio Di Narzo wrote:
>
> > Dear all,
> > I'm indirectly faced with the fact that setting the 'tsp' attribute of
> > an object modifies its class definition:
> >> class( structure(1:2, tsp=c(1,2,1), class=c("myts","ts")) )
> > [1] "ts"   "myts"
> >
> > In general, this is of really little (ok, I admit: totally no)
> > interest for me because 'myts' class is added just after assigning the
> > 'tsp' attribute (by calling ts).
> > However, this behaviour gives me troubles when re-loading a previously
> > deparsed object, so that:
> >> x <- ts(1:2)
> >> class(x) <- c("myts", class(x))
> >> dput( x , "temp.dat")
> >> class(dget("temp.dat"))
> > [1] "ts"   "myts"
> >> unlink("temp.dat")
> >
> > In other words, my real problem should be restated as: how to safely
> > dump (and then load) an object which has a (perhaps valid) "tsp"
> > attribute?
> > More generally: can someone suggest me a safer way to dump/restoring R objects?
>
> save/load.

Ok. That seems to be the final statement: to be sure about the result,
I have to use binary files for storing R objects (even pure data
objects with attached attributes) instead of dumped R code.
I will accept that (infact, as I can read in 'save' help page, those
binaries should be portable across R platforms) and avoid boring you
anymore :-)

>
> ?dput comes with copious warnings about the problems of doing what you are
> attempting, so I wonder why you are surprised.

I've seen. That's because I've asked for suggestions, and not called
this a 'bug' or a 'nonsense' behaviour.

>
> --
> Brian D. Ripley,                  ripley a 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 272866 (PA)
> Oxford OX1 3TG, UK                Fax:  +44 1865 272595
>


-- 
Antonio, Fabio Di Narzo
Ph.D. student at
Department of Statistical Sciences
University of Bologna, Italy