Dede Greenstein
2004-Sep-03 19:00 UTC
[R] contrast/test statements in polynomial mixed model
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Dede Greenstein
2004-Sep-07 17:05 UTC
[R] contrast/test statements in polynomial mixed model
Hello I am having some trouble figuring out how to write contrast/test syntax for the following mixed model regression y ~ group*age + group*age^2 random =~1|ID (i have centered the age variable & there are only 2 groups) the contrast i am trying to construct should compare the overall shape of the 2 groups -- in SAS, this does the trick -- test 'group difference in shape' age_squared*group1 -1; age_cent*group 1 -1 Suggestions would be greatly appreciated Thanks in advance Dede Greenstein