On 12/17/2007 9:06 AM, Oleg Sklyar wrote: > Dear Patrick, > > Firstly, and most importantly, I do not think that your post qualified > for Rd! Please use the correct mail list for such things: R-help. I do > not think anybody on Rd wants mailboxes clogged with irrelevant > messages.
Since Patrick's message was about changes to the documentation, I think it is relevant to this list. Duncan Murdoch > Back to your question: it is not clear if you are confused, or your > 'user' is confused, but all three help pages look pretty clear and > straight forward to me. Moreover, I do not see any connection between > attach and library, which you find logical: > > - load - the general use of this one is to load external data sets, e.g. > load serialised R object(s) (as the example shows). Until you load, you > cannot use the object as it has no relation to the R session and can be > e.g. a file sitting somewhere on a network > > - attach - the general use of this one would be to access elements of a > data set directly, without the data set name specifier and the accessor > operator, such as $, thus as the help page states - it is used to add > the data set to the search path (as the example shows). If you look at > the example, you do not have to call attach to be able to use data, data > could have existed there before and what you effectively get with attach > is a more convenient way of dealing with the data > > - library - is used to load *and* attach an R package, which is not > exactly the same as a serialised R object(s), but a full set of other > functionality. Attaching packages is just a part of the loading process, > which occurs basically when the package becomes visible to the user. > Same as with load, you cannot use the package until you load it. There > is not a hint of similarity between loading a package and attaching a > data set as I see it. > > Regards, > Oleg > > On Mon, 2007-12-17 at 11:00 +0000, Patrick Burns wrote: >> I recently had a discussion with a user about loading >> and attaching in R. I was surprised that the help files >> don't provide a very clear picture. >> >> From my point of view 'load' and 'attach' are very >> similar operations, the difference being that 'attach' >> creates a new database on the search list while 'load' >> puts all the objects into the global environment. >> >> The help file for 'load' is inexplicit that this is what >> happens. The 'load' and 'attach' help files neither refer >> to the other in their See Also. >> >> Furthermore, the 'library' help file talks about "loading" >> packages. I would suggest that it should use "attaching" >> as that is the analogous operation. >> >> None of these three help files (nor that of 'save') has a >> Side Effects section. Personally I think that all help files >> should have a Side Effects section (to make it clear to >> new users what side effects are and that they are not a >> good thing for most functions to have). I can understand >> there could be another point of view on that. However, I >> definitely think that there should be a Side Effects section >> in the help files of functions whose whole point is a side >> effect. >> >> Patrick Burns >> [EMAIL PROTECTED] >> +44 (0)20 8525 0696 >> http://www.burns-stat.com >> (home of S Poetry and "A Guide for the Unwilling S User") >> >> ______________________________________________ >> R-devel@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
