Whenever I have used a where statement with SAS procedures, it has always been with syntax like where notmissing=0; Try that with Glimmix and let know if it works. Brandy ... View more

Another option is Proc CALIS with a path analysis model.  If don't want to restrict the paths to be equal for X1 and X2, use different path names. ods html path="c:\temp"; ods graphics on; proc calis data=thedata method=ml kurtosis modification plots=residuals effpart;                                              path                                                                                                                                                                                                                                                                X3 X4   ---> X1= P_X3_X1N2 P_X4_X1N2 ,                                               X3 X4   ---> X2= P_X3_X1N2 P_X4_X1N2;                                                                                                                     var X1-X4; TestPath=P_X3_X1N2 - P_X4_X1N2; testfunc TestPath;                                                                                run;                                                                                                                                    ods graphics off; ods html close;  I think the test statistic will be a Wald statistic. Hope this helps. Brandy    ... View more

Hi Dingdang, Try delimiter=tab.  Hope this helps. Brandy ... View more