I'm experimenting with proc mcmc in SAS EG to build ERS and MRS for MNRM(multidimensional nominal response model).
I've referenced the following paper:Using SAS PROC MCMC for Item Response Theory Models Using SAS PROC MCMC for Item Response Theory Models - PMC (nih.gov)
Hello,
It might have something to do with missing values.
Try using INITIAL= option in MODEL statement of PROC MCMC.
SAS/STAT 15.3 User's Guide
The MCMC Procedure
MODEL Statement
https://go.documentation.sas.com/doc/en/pgmsascdc/9.4_3.5/statug/statug_mcmc_syntax09.htm
Also possible (didn't check your code very well).
Prior distribution for sigma (variance) is specified as normal.
In this case, it might be possible to have negative variance, which results in problem for calculating log-likelihood.
Modify into other prior distribution, which has range above zero.
BR, Koen
It's always a good idea to show the error in the log.
I don't see the variables z1-z5 in the program, although they could be in the input data set. Should the equation for p[k] be
p[k] = z[k]/(z[1]+z[2]+z[3]+z[4]+z[5]);
Registration is open! SAS is returning to Vegas for an AI and analytics experience like no other! Whether you're an executive, manager, end user or SAS partner, SAS Innovate is designed for everyone on your team. Register for just $495 by 12/31/2023.
If you are interested in speaking, there is still time to submit a session idea. More details are posted on the website.
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.