I have a dataset in this format:
Factor A is a between subject factor (with 2 levels - High and Low). Factor B is a within subject factor (with 3 levels - High , Moderate and Low).
I want to run a mixed model with nested random effects factor.
The code that I am using is:
proc mixed data=data.mydata; class FactorA FactorB; model DV = FactorA|FactorB; random FactorB(FactorA) FactorB*FactorA(FactorA); lsmeans FactorA|FactorB; run;
The log states: Estimated G matrix is not positive definite. I also do not get any of the p-values (only a '.' is displayed).
Furthermore in the output tables, I see that DF = 0. I have a hunch that this is what is symptomatic of the error. But I have been unable to figure out why this is happening. Any leads will be appreciated. Thanks.