Documentation Example 2 for PROC MIXED
/****************************************************************/
/* S A S S A M P L E L I B R A R Y */
/* */
/* NAME: MIXEX2 */
/* TITLE: Documentation Example 2 for PROC MIXED */
/* Repeated Measures */
/* PRODUCT: STAT */
/* SYSTEM: ALL */
/* KEYS: Mixed Linear Models */
/* PROCS: MIXED */
/* DATA: */
/* */
/* SUPPORT: Tianlin Wang */
/* REF: */
/* MISC: */
/* */
/****************************************************************/
*---------------Repeated Measures Example-----------*
| Data represent a repeated measures example where |
| an unstructured variance matrix is fit. Data are |
| from Pothoff and Roy (1964) and are analyzed by |
| Jennrich and Schluchter (1986). |
*---------------------------------------------------*;
data pr;
input Person Gender $ y1 y2 y3 y4;
y=y1; Age=8; output;
y=y2; Age=10; output;
y=y3; Age=12; output;
y=y4; Age=14; output;
drop y1-y4;
datalines;
1 F 21.0 20.0 21.5 23.0
2 F 21.0 21.5 24.0 25.5
3 F 20.5 24.0 24.5 26.0
4 F 23.5 24.5 25.0 26.5
5 F 21.5 23.0 22.5 23.5
6 F 20.0 21.0 21.0 22.5
7 F 21.5 22.5 23.0 25.0
8 F 23.0 23.0 23.5 24.0
9 F 20.0 21.0 22.0 21.5
10 F 16.5 19.0 19.0 19.5
11 F 24.5 25.0 28.0 28.0
12 M 26.0 25.0 29.0 31.0
13 M 21.5 22.5 23.0 26.5
14 M 23.0 22.5 24.0 27.5
15 M 25.5 27.5 26.5 27.0
16 M 20.0 23.5 22.5 26.0
17 M 24.5 25.5 27.0 28.5
18 M 22.0 22.0 24.5 26.5
19 M 24.0 21.5 24.5 25.5
20 M 23.0 20.5 31.0 26.0
21 M 27.5 28.0 31.0 31.5
22 M 23.0 23.0 23.5 25.0
23 M 21.5 23.5 24.0 28.0
24 M 17.0 24.5 26.0 29.5
25 M 22.5 25.5 25.5 26.0
26 M 23.0 24.5 26.0 30.0
27 M 22.0 21.5 23.5 25.0
;
proc mixed data=pr method=ml covtest;
class Person Gender;
model y = Gender Age Gender*Age / s;
repeated / type=un subject=Person r;
run;
/* first-order autoregressive */
proc mixed data=pr method=ml;
class Person Gender;
model y = Gender Age Gender*Age / s;
repeated / type=ar(1) sub=Person r;
run;
/* random coefficients model */
proc mixed data=pr method=ml;
class Person Gender;
model y = Gender Age Gender*Age / s;
random intercept Age / type=un sub=Person g;
run;
proc mixed data=pr method=ml covtest;
class Person Gender;
model y = Gender Age Gender*Age / s;
repeated / type=cs subject=Person r;
run;
/* compound symmetry specified on RANDOM statement */
proc mixed data=pr method=ml;
class Person Gender;
model y = Gender Age Gender*Age / s;
random Person;
run;
proc mixed data=pr method=ml;
class Person Gender;
model y = Gender Age Gender*Age / s;
repeated / type=cs subject=Person group=Gender;
run;