[R] Initialize many variables to NUL, check whether an object exist

Gabor Csardi csardi at rmki.kfki.hu
Mon Apr 14 15:53:51 CEST 2008

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 ?



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

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