Hello,
Output files ending in _fstat<number>.nii.gz will contain
randomise's fstat values - it sounds like randomise may not have run
the ftests, the 9 outputs you are seeing will probably correspond to
the 9 t-contrasts. When randomise is run it should print on the screen
the number and type of contrast it is currently analysing - did you
get a message saying something like:
<number> permutations required for exhaustive test of f-test 1?
Many Regards
Matthew
> 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
> [log in to unmask]
>
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