Hi Shady,
Try assembling the design as this:
EV1: Group 1 (coded as 0/1)
EV2: Group 2 (coded as 0/1)
EV3: Group 3 (coded as 0/1)
EV4: Sex (coded as +1/-1)
EV5: Site (coded as +1/-1)
The contrasts to compare the three groups are then:
C1: [1 -1 0 0 0]
C2: [1 0 -1 0 0]
C3: [0 1 -1 0 0]
C4: [-1 1 0
Greetings,
I want to design a matrix that contains 3 fixed factors. The first is
diagnosis (3 levels), the second is gender (2 levels), and the last is
imaging site (2 levels). However, the thing is that the imaging site factor
only applies to only one level of the diagnosis factor (i.e. patients
