[R] How to extract the variable names from a formula

[Marc Schwartz]

On Nov 19, 2009, at 9:28 PM, Yihui Xie wrote:

> Hi all,
>
> Suppose I have a formula: a = log(y) ~ x1 + I(x2^2)
>
> How can I extract the original variable names 'y', 'x1', 'x2' from
> this formula? Thanks a lot!
>
> Regards,
> Yihui


 > all.vars(a)
[1] "y"  "x1" "x2"

See ?all.vars

HTH,

Marc Schwartz