Following this anova:
. anova f sys tc sys*tc
Number of obs = 180 R-squared = 0.9399
Root MSE = 1.61981 Adj R-squared = 0.9359
Source | Partial SS df MS F Prob > F
-----------+----------------------------------------------------
Model | 6891.18382 11 626.471256 238.77 0.0000
|
sys | 1347.15634 2 673.578172 256.72 0.0000
tc | 4939.60999 3 1646.53666 627.54 0.0000
sys*tc | 604.417487 6 100.736248 38.39 0.0000
|
Residual | 440.796853 168 2.62379079
-----------+----------------------------------------------------
Total | 7331.98067 179 40.9607859
I want to compare systems 1,2 & 3 at time 4. The design matrix is
. test, showorder
Order of columns in the design matrix
1: _cons
2: (sys==1)
3: (sys==2)
4: (sys==3)
5: (tc==1)
6: (tc==2)
7: (tc==3)
8: (tc==4)
9: (sys==1)*(tc==1)
10: (sys==1)*(tc==2)
11: (sys==1)*(tc==3)
12: (sys==1)*(tc==4)
13: (sys==2)*(tc==1)
14: (sys==2)*(tc==2)
15: (sys==2)*(tc==3)
16: (sys==2)*(tc==4)
17: (sys==3)*(tc==1)
18: (sys==3)*(tc==2)
19: (sys==3)*(tc==3)
20: (sys==3)*(tc==4)
and I tried the following:
mat input c2 = (0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,-1,0,0,0,0 \ 0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,-1 \ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,-1)
. test, test(c2)
( 1) sys[1]*tc[4] - sys[2]*tc[4] = 0
( 2) sys[1]*tc[4] - sys[3]*tc[4] = 0
( 3) sys[2]*tc[4] - sys[3]*tc[4] = 0
Constraint 1 dropped
Constraint 2 dropped
Constraint 3 dropped
. test, test(c2) mtest(sidak)
_mtest: 0 valid tests
r(198);
Is there anyway that I can carry out this comparison?
I am usung Stata 10.
Ted.
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