Dear all,
Just a quick question about setting a f contrast for 3 group comparison in randomise. I apologize as I have seen similar questions been asked before but none of them answered my specific question.
I set the following design.con to look at all possible two-way differences.
/Controls Relatives Patients
/Matrix
1 -1 0
-1 1 0
1 0 -1
-1 0 1
0 1 -1
0 -1 1
When I tried to set a f contrast
/Matrix
1 -1 0
0 1 -1
I received the following error message:
'ERROR: Program failed
An exception has been thrown number of columns in f-contrast matrix doesn't match number of rows in t-contrast matrix!'
When I included only three contrasts in the design.con (a priori hypothesis C>relatives>ill) using the same fts file, randomise ran just fine. Assuming that the f contrast uses the original EVs from the design matrix rather than the set contrasts by the design.con, I am not very sure why I received this message.
Thank you in advance.
Best wishes
Rali
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