
Hey,
I am having trouble with lmer.  I am looking at the presence/absence of water shrews against habitat and other factors e.g
so I used this:
m1<-lmer(Presencebsence~Habitatype*Width+(1|Sitename))summary(m1)
But i keep getting this error up
Error in mer_finalize(ans) : Downdated X'X is not positive definite, 16.> summary(m1)Error in asMethod(object) : matrix is not symmetric [1,2]
What does this mean and now can I fix it?
Sophie 		 	   		  
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