[R] Help : glm p-values for a factor predictor

[Bob O'Hara]

It might help if you provided the code you used. It's possible that
you didn't use direction="backward" in stepAIC(). Or if you did, it
was still running, so whatever else you try will still be slow. The
statement "R provides only the pvalues for each level" is wrong: look
at the anova() function.

Bob

On 29 June 2017 at 11:13, Benoît PELE <benoit.pele at acoss.fr> wrote:
> Hello,
>
> i am a newby on R and i am trying to make a backward selection on a
> binomial-logit glm on a large dataset (69000 lines for 145 predictors).
>
> After 3 days working, the stepAIC function did not terminate. I do not
> know if that is normal but i would like to try computing a "homemade"
> backward with a repeated glm ; at each step, the predictor with the max
> pvalue would be excluded until reaching a set of 20 predictors for
> example.
>
> My question is about the factor predictors with several levels. R provides
> only the pvalues for each level whereas i need an overall pvalue for
> testing the predictor.
>
> On internet, the only solution i found suggests to compute a Khi2
> log-likelihood test between the complete model and the model without the
> factor predictor to emphasize its relevance.
>
> Do you know other ways? Another R package managing this kind of issue?
>
> Thank you and best regards, Benoit.
>         [[alternative HTML version deleted]]
>
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-- 
Bob O'Hara
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