[Rd] compress defaults for save() and save.image()

[Roger D. Peng]

Prof Brian Ripley wrote:
> I have changed the default in save() to compress = !ascii.  This seems 
> quite safe, as almost always save() is called explicitly and people will
> appreciate that it might take a little time to save large objects (and 
> depending on your system, compression could even be faster).

I'm in favor of such a change.  I almost always explicitly set `compress = 
TRUE'.  When I don't use it, it's because I want to be able to load large 
objects quickly and I've noticed that loading uncompressed workspaces can be 
quite a bit faster.  Usually though, the savings in disk space is worth the 
small penalty in loading time.

> 
> Should we also change the default in save.image()?  That is almost always 
> used implicitly, via q(), a menu ....  There are arguments that it is a 
> more serious change so should not be done at the end of the release cycle, 
> and also that large .RData files are something people would want to avoid.

I rarely use `save.image()' except to occasionally dump data during a long run 
for crash recovery purposes.  I don't think changing the defaults would make a 
difference to me.

> 
> BTW, the defaults can be changed via options() (see ?save): has anyone 
> ever found that useful?

I was not even aware of this!

> 
> And whilst I am feeling curious, has anyone used save(ascii = TRUE) in 
> recent years?
> 

I don't think I've ever used this feature.

-roger

-- 
Roger D. Peng  |  http://www.biostat.jhsph.edu/~rpeng/