Large discrepancies in the same object being saved to .RData

On Sun, 11 Jul 2010, Tony Plate wrote:

Another way of seeing the environments referenced in an object is using 
str(), e.g.:

f1 <- function() {

+ junk <- rnorm(10000000)
+ x <- 1:3
+ y <- rnorm(3)
+ lm(y ~ x)
+ }

v1 <- f1()
object.size(f1)

1636 bytes

grep("Environment", capture.output(str(v1)), value=TRUE)

[1] "  .. ..- attr(*, \".Environment\")=<environment: 0x01f11a30> "
[2] "  .. .. ..- attr(*, \".Environment\")=<environment: 0x01f11a30> "

'Some of the environments in a few cases': remember environments have 
environments (and so on), and that namespaces and packages are also 
environments.  So we need to know about the environment of 
environment(v1$terms), which also gets saved (either as a reference or 
as an environment, depending on what it is).

And this approach does not work for many of the commonest cases:

f <- function() {

+ x <- pi
+ g <- function() print(x)
+ return(g)
+ }

g <- f()
str(g)

function ()
  - attr(*, "source")= chr "function() print(x)"

ls(environment(g))

[1] "g" "x"

In fact I think it works only for formulae.

-- Tony Plate

On 7/10/2010 10:10 PM, Bill.Venables at csiro.au wrote:

Well, I have answered one of my questions below.  The hidden
environment is attached to the 'terms' component of v1.

Well, not really hidden.  A terms component is a formula (see 
?terms.object), and a formula has an environment just as a closure 
does.  In neither case does the print() method tell you about it -- 
but ?formula does.