[R] Selecting the "non-attribute" part of an object

[Jonathan Dushoff]

I have two matrices, generated by R functions that I don't understand.
 I want to confirm that they're the same, but I know that they have
different attributes.

If I want to compare the dimnames, I can say

> identical(attr(tm, "dimnames"), attr(tmm, "dimnames"))
[1] FALSE

or even:

> identical(dimnames(tm), dimnames(tmm))
[1] FALSE

But I can't find any good way to compare the "main" part of objects.

What I'm doing now is:

> tm_new <- tm
> tmm_new <- tmm

> attributes(tm_new) <- attributes(tmm_new) <- NULL

> identical(tm_new, tmm_new)
[1] TRUE

But that seems very inaesthetic, besides requiring that I create two
pointless objects.

I have read ?attributes, ?attr and some web introductions to how R
objects work, but have not found an answer.

Thanks for any help.