Hi David,
You must have made that tlrc dataset from another one in
some way. And if that other one has an +orig dataset, you
can use that transformation to create a corresponding one
for the new dataset.
So you have old+orig, old+tlrc and new+tlrc, and you want
new+orig. Try:
3dfractionize -template old+orig -input new+tlrc -warp old+tlrc -clip 0.2
The resulting new+orig dataset will have a grid template
based on old+orig. You can use another dataset there if
you prefer.
- rick