[R] glm prb (Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") : )

[David Winsemius]

On Aug 29, 2010, at 3:13 PM, moleps wrote:

>
> glm(A~B+C+D+E+F,family = binomial(link =  
> "logit"),data=tre,na.action=na.omit)
> Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") :
>  contrasts can be applied only to factors with 2 or more levels
>
> however,
>
> glm(A~B+C+D+E,family = binomial(link =  
> "logit"),data=tre,na.action=na.omit)
>
> runs fine
>
> glm(A~B+C+D+F,family = binomial(link =  
> "logit"),data=tre,na.action=na.omit)
>
> runs fine
>
>
>
> glm(A~E+F,family = binomial(link =  
> "logit"),data=tre,na.action=na.omit)
> Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") :
>  contrasts can be applied only to factors with 2 or more levels
>
> Why is this? Could it be due to collinearity between the two?

Perhaps, at least to the extent that the term "collinearity" is an  
appropriate term for factor interactions. The obvious question at this  
point is: What does:

with( tre, table(E,F) )   # show?

-- 

David Winsemius, MD
West Hartford, CT