I have been trying to get predicted probability for each count. I am putting code "predicted=" after model statement but that is giving me the mean of poisson. How can I get predicted probability based on poisson for each count and graph it?
data world;
input scores @@;
datalines;
4 3 3 3 2 4 2 0 3 3 3 2 4 2
1 1 1 3 7 3 2 2 2 5
..........
;
proc genmod data=world;
model scores= /dist=poisson link=log;
output out=new predicted=predictedscores;
run;
quit;
Diy then,
data probs;
set new;
prob = pdf("Poisson", scores, predictedScores);
run;
If you have a SAS/ETS license, proc countreg provides option prob= in the output statement to compute those probabilities.
I don't have SAS/ETS. I am using SAS studio university edition. I tried countreg, didn't work.
Diy then,
data probs;
set new;
prob = pdf("Poisson", scores, predictedScores);
run;
I'd say that your code is doing exactly what you've specified: you've specified an intercept-only model, so predictions for all observations will be equal to the intercept.
I don't have an idea about what you would rather be doing, but I'm guessing it might be more along the lines of your other question
https://communities.sas.com/t5/SAS-Statistical-Procedures/proc-genmod-graphics-for-count-data-model-..., where you've gotten two good solutions.
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