[R] how "big" (in RAM and/or disk storage) is each of these objects in a list?

[Paul Johnson]

Greetings, friends (and others :) )

We generated a bunch of results and saved them in an RData file. We
can open, use, all is well, except that the size of the saved file is
quite a bit larger than we expected.  I suspect there's something
floating about in there that one of the packages we are using puts in,
such as a spare copy of a data frame that is saved in some subtle way
that has escaped my attention.

Consider a list of objects. Are there ways to do these things:

1. ask R how much memory is used by the things inside the list?

2.   Does "as.expression(anObject)" print everything in there? Or, is
there a better way to convert each thing to text or some other format
that you can actually read line by line to see what is in there, to
"see" everything?

If there's no giant hidden data frame floating about, I figure I'll
have to convert symmetric matrices to lower triangles or such to save
space.  Unless R already is automatically saving a matrix in that way
but just showing me the full matrix, which I suppose is possible. If
you have other ideas about general ways to make saved objects smaller,
I'm open for suggestions.

-- 
Paul E. Johnson
Professor, Political Science
1541 Lilac Lane, Room 504
University of Kansas