BookmarkSubscribeRSS Feed
🔒 This topic is solved and locked. Need further help from the community? Please sign in and ask a new question.
Nebulus
Calcite | Level 5

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;
random _residual_;
lsmeans season /cl diff plot=meanplot adjust=tukey;
lsmeans climate /cl diff plot=meanplot adjust=tukey;
run;

 

Proc means gives me the correct values.

 

Below is the paritial output showing the issue with the intercept and LSMEANS.1.png2.png3.png4.png

 

 

Can anyone explain what is happening. I'm completely perplexed at this point. I would expect to get positive LSMEANS for parasitism rates..

 

 

1 ACCEPTED SOLUTION

Accepted Solutions
PaigeMiller
Diamond | Level 26

These are on the logit scale. You need to un-transform the results.

--
Paige Miller

View solution in original post

2 REPLIES 2
PaigeMiller
Diamond | Level 26

These are on the logit scale. You need to un-transform the results.

--
Paige Miller

Ready to join fellow brilliant minds for the SAS Hackathon?

Build your skills. Make connections. Enjoy creative freedom. Maybe change the world. Registration is now open through August 30th. Visit the SAS Hackathon homepage.

Register today!
What is ANOVA?

ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.

Find more tutorials on the SAS Users YouTube channel.

Discussion stats
  • 2 replies
  • 1841 views
  • 0 likes
  • 3 in conversation