Hi all,
I have an RCBD experiment with a two-way factorial treatment design, which are fully randomized within each block. I also don't have subsampling.
My question is: In the random statement of the proc Glimmix, should I include only block, or block block*factor(a) and block*factor(b)?
Thank you in advance for the support,
Gustavo
I would start with the more specific random statement, and reduce as needed. In other words:
RANDOM intercept A B/subject=block;
would be the first I would try. If there is sufficient data and variability to estimate all of these components, then you are done. If however, you get the message that the G matrix isn't positive definite, or there are zero values for the block*A or block*B variance components, you can reduce the statement and remove the zero-valued variance component terms.
Steve Denham
I would start with the more specific random statement, and reduce as needed. In other words:
RANDOM intercept A B/subject=block;
would be the first I would try. If there is sufficient data and variability to estimate all of these components, then you are done. If however, you get the message that the G matrix isn't positive definite, or there are zero values for the block*A or block*B variance components, you can reduce the statement and remove the zero-valued variance component terms.
Steve Denham
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