Dear All:
I know this issue has been discussed in the list, but I still have
questions.
I have 3 groups: A: control; B: patients 1; and C: patients 2.
group A B C
1 1 0 0
1 1 0 0
1 1 0 0
1 1 0 0
1 1 0 0
2 0 1 0
2 0 1 0
2 0 1 0
2 0 1 0
2 0 1 0
3 0 0 1
3 0 0 1
3 0 0 1
3 0 0 1
3 0 0 1
(We have > 170 subjects totally)
Contrast for t- and f- test
A-B: 1 -1 0
B-A: -1 1 0
A-C: 1 0 -1
C-A: -1 0 1
B-C: 0 1 -1
C-B: 0 -1 1
A 1 0 0 F
B 0 1 0 F
C 0 0 1 F
I run randomise with following options:
randomise -i input -o output -m mask -d design.mat -t design.con -f
design.fts -n 5000 -c 2.0 -F 2.0 -V
I got 9 outputs. I know the first 6 is for the 6 t-tests specified in
above Contrast. My question is: how to interpret the last three
outputs? Which one is the result of the F test?
I also want to assess if the FA of male and female patients show
different changes relative to male and female controls, respectively.
I made following changes for design:
group A B C Gender (0 for females and 1 for males)
1 1 0 0 0
1 1 0 0 0
1 1 0 0 0
1 1 0 0 1
1 1 0 0 1
2 0 1 0 0
2 0 1 0 1
2 0 1 0 1
2 0 1 0 1
2 0 1 0 1
3 0 0 1 0
3 0 0 1 0
3 0 0 1 1
3 0 0 1 1
3 0 0 1 1
Question: How to set the contrast for assessing the interaction of
gender and group on FA values?
Best Regards
Jiansong
===============
Jiansong Xu, M.D., Ph.D.
Dept. of Psychiatry
Yale Medical School
2 Church St., Suite 215
New Haven, CT 06519
203-785-5306
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