R help - Apr 2008 - Initialize many variables to NUL, check whether an object exist

Hi,

Two questions:

A) I need to initialize many variables to NULL. So I created variable_names
<- c("a1", "a2"). What can I do to variable_names so that
variable a1 is
NULL and a2 is NULL ?
B) How can I check whether an object exist ?

Thanks
Stanley

	[[alternative HTML version deleted]]

On Mon, Apr 14, 2008 at 09:47:49PM +0800, Ng Stanley
wrote:
> Hi,
> 
> Two questions:
> 
> A) I need to initialize many variables to NULL. So I created variable_names
> <- c("a1", "a2"). What can I do to variable_names so
that variable a1 is
> NULL and a2 is NULL ?
for (n in variable_names) assign(n, NULL)
> B) How can I check whether an object exist ?
help.search("exists")

G.
> Thanks
> Stanley
> 
> 	[[alternative HTML version deleted]]
> 
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-- 
Csardi Gabor <csardi at rmki.kfki.hu>    UNIL DGM