```Date: Fri, 11 Mar 2011 21:21:42 -0500 Reply-To: R B Sender: "SAS(r) Discussion" From: R B Subject: Estimating Difference in Centroids in Multivariate Linear Mixed Model Content-Type: text/plain; charset=ISO-8859-1 Hi, Dale has shown how to contruct a multivariate test employing the CONTRAST statement in MIXED. CONTRAST statements, however, do not provide actual estimates (e.g. difference in centroids between groups). Is there any way to produce the same multivariate test employing the ESTIMATE statement in order to obtain the difference in centroids? I provide a little simulation along with MIXED code below to help concretize my question. Thanks, Ryan -- data test; seed = 987624; do subject = 1 to 1000; group = ranbin(seed,1,0.50); random_eff = sqrt(0.3)*rannor(seed); do y_indic = 1 to 3; err = rannor(seed); y = 1.0*(y_indic=1) + 2.0*(y_indic=2) + 3.0*(y_indic=3) + 1.0*(y_indic=1)*(group=0) + 2.0*(y_indic=2)*(group=0) + 3.0*(y_indic=3)*(group=0) + random_eff + err; output; end; end; run; proc mixed data = test; class y_indic group; model y = y_indic y_indic*group / s noint; repeated y_indic / subject = subject type = un; contrast 'multivariate test' y_indic*group -1 1 0 0 0 0, y_indic*group 0 0 -1 1 0 0, y_indic*group 0 0 0 0 -1 1; run; ```

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