[R] vif function using lm object

Liviu Andronic landronimirc at gmail.com
Fri Dec 23 18:53:16 CET 2011


On Wed, Dec 21, 2011 at 9:28 AM, arunkumar1111 <akpbond007 at gmail.com> wrote:
> Hi,
>
>   can anyone please explain why the vif should have more than 2 terms.
>
> *vif.lm(lmobj) : model contains fewer than 2 terms*
>
> why it is throwng error if it is one variable.
>
The _VIF_ is a measure of _multicollinearity_, which occurs between
two or more predictors in a regression model. In other words, you
cannot have collinearity in a single predictor.

Also, to compute the VIF you need to regress one regressor on all the
remaining regressors. If you have a single regressor, then you cannot
estimate a VIF.

See the related articles on Wikipedia.

Regards
Liviu



>
>
>
> -----
> Thanks in Advance
>        Arun
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