Loading of namespace on load of .Rdata (was strange behaviourof load)

Apologies - I was not trying to correct you Brian, but to explore how the situation could arise. I'm sure you had a good idea why the namespace (or a reference to it) had been saved, but this was not clear to me and I thought, possibly not to others either.

Thanks for putting me right over parent environments vs. enclosures - again I was not trying to correct you with the point I made there, but to trace back where the reference to the namespace might have come from in Giovanni's case.

I think the issues raised are still of interest...

Heather

Prof Brian Ripley <ripley at stats.ox.ac.uk> 01/18/06 01:31pm >>>

[Lines wrapped for legibility and R-help removed as it is not an 
appropriate list.]

Last week Giovanni Parrinello posted a message asking why various 
packages were loaded when he loaded an .Rdata file. Brian Ripley replied 
saying he thought it was because the saved workspace contained a 
reference to the namespace of ipred. (Correspondence copied below).

This begs the question: how did the reference to the namespace of ipred 
come to be in the .Rdata file? Brian did say it is likely to be because 
the workspace contained object(s) saved with environment the namespace 
of ipred - but how would this come about?

In this case I think is because the .Rdata file contained an object 
whose *parent* environment was the namespace of ipred. Take the 
following example from ?bagging (having loaded ipred):

Excuse me: environments do not have parents but enclosures according to 
?environment.

Of course, the environment of mod is itself an object, and so my statement 
holds true.  Saving a workspace saves all the objects (possibly as 
references) whether named or not.  I was fully aware that the namespace 
was likely to be up the environment tree of a named object when I chose my 
words carefully.

data(BreastCancer)

mod <- bagging(Class ~ Cl.thickness + Cell.size

+                 + Cell.shape + Marg.adhesion
+                 + Epith.c.size + Bare.nuclei
+                 + Bl.cromatin + Normal.nucleoli
+                 + Mitoses, data=BreastCancer, coob=TRUE)

environment(mod$mtrees[[1]]$btree$terms)

<environment: 024E8138>

parent.env(environment(mod$mtrees[[1]]$btree$terms))

<environment: namespace:ipred>

parent.env is a very confusing name.  To quote the draft R language 
definition:

 	`The parent.env function may be used to access the enclosure
 	of an environment.'

[...]

Brian D. Ripley,                  ripley at 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