[R] attach and detach question

[Gabor Grothendieck]

There is an example of saving just two objects in the example
section of ?save

To check whether an object of a given name exists see ?exists

On 7/7/06, markleeds at verizon.net <markleeds at verizon.net> wrote:
>
> I have a large R program that I am constantly running over and over again. At the beginning of this program, I create a hige matrix and a huge dataframe but these are constant. What I mean by constant is that, if I run the program over later, I really should just use the old matrix and dataframe ( if they exist ) that were created in a previous run so that the program doesn't have to spend time creating them. Unfortunately, I don't know how to do this so things take foreeer because every time i do a new run, i recreate these objects and the boss is getting a little annoyed. I know/think that I should use attach and detach commands  but
>
> 1) i can't find an example somewhere of
> just saving two objects rather than the whole session.
> i've looked and looked and i can't find it.
>
> 2) if i am able to save these two objects, i was hoping that it
> would be possible to write code inside my R program
> that basically says, "if these objects already exist in
> such and such database, then skip over this section of the code
> that creates them".
>
> if someone has some code or a page number or reference, this is fine because i used to do pretty much this in Splus so think i can figure it out if i can just find an example.  thanks a lot.
>
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