03-06-2018 08:08 PM - edited 03-06-2018 08:55 PM
I'm running a GLMM with a binomial error distribution on proportion parasitism data values which range 0-1 and are not transformed.
I'm having a problem where I'm getting a negative intercept and thus my LSMEANS are negative, which shouldn't be the case. Unless it should be the case due to the link function...?
The model code looks like this
proc glimmix data=final ic=q;
class interval climate season site;
model parasitism = interval(season) season climate tot_nymprev / dist=bin link=logit s;
random intercept / subject=site;
random interval / subject=site residual;
lsmeans season /cl diff plot=meanplot adjust=tukey;
lsmeans climate /cl diff plot=meanplot adjust=tukey;
Proc means gives me the correct values.
Below is the paritial output showing the issue with the intercept and LSMEANS.
Can anyone explain what is happening. I'm completely perplexed at this point. I would expect to get positive LSMEANS for parasitism rates..
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