本人做毕业论文数据分析，资料用到带时变协变量重复测量的混合线性模型分析，SAS程序如下：
proc mixed data=Hsp method=ml;
class group time piglet;
model y=group time time*w group0*w w/S;
repeated time/type=un subject=piglet R;
lsmeans time group /pdiff;
Run;
可是程序被终止，弹出：WARNING: Stopped because of too many likelihood evaluation
本人对SAS掌握甚浅，请各位大侠指点，谢谢！