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Calcite | Level 5

Can anyone tell me what the following error means? 


WARNING: The R matrix depends on observation order within subjects. Omitting observations from
the analysis because of missing values can affect this matrix. Consider using a
classification effect in the RANDOM _RESIDUAL_ statement to determine ordering in the R


I am attempting to run repeated measures on some data. The design was 20 animals blocked into light and heavy bodyweights, then assigned to 1 of 2 treatments withing each block. The animals had biopsies at 5 time points and gene expression was measured on 8 genes at each point. Attached is the SAS input as well as the output. I am not sure my denominator DF are correct and this may be associated with the error? Any help would be greatly appreciated.

SAS Employee

When you have missing observations on the RANDOM _RESIDUAL_ statement in GLIMMIX then the procedure generates the warning message. Considering change the RANDOM _RESIDUAL_ to -


Proc glimmix data = JessicaPCR;


Model AMPK = TRT|DAY/ddfm = KR;

random intercept / subject=BLOCK;

random intercept / subject=ID*TRT;

random day /subject = ID*TRT type=arh(1) residual;

LSMEANS TRT|DAY/ pdiff lines;

nloptions tech=nrridg;



The above RANDOM statement should make note go away.



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