Hello,
When I used the -EPI option of 3dAllineate, my understanding was that it restricts the scaling and shearing only in y-direction. For scaling it is easy to understand, but for shearing, what exactly is this restriction? I asked because I saw an output of final fit parameter like the following:
+ Final fine fit Parameters:
x-shift=-0.6944 y-shift= 0.0726 z-shift= 0.1699
z-angle=-0.3022 x-angle= 1.6423 y-angle= 0.6659
x-scale= 1.0000 y-scale= 0.9857 z-scale= 1.0000
y/x-shear=-0.0010 z/x-shear= 0.0032 z/y-shear= 0.0000
It seems that z/x-shear has also non-zero value. Is this what it is supposed to be?
Thanks!