[Insight-users] Final transformation question

[brian avants]

Anja

This is called composition.

In your example, you would apply the map from C to B to the map from B to A.
Then you would add the result to the map from C to B.    The result is
a map from C to A, allowing you to warp A to C.

That is , phi_CA(x) = phi_BA(phi_CB(x))

An algorithm:

1.  apply phi_CB to phi_BA to get phi_BA_prime -- this pulls phi_BA to
the space of C.
2.  phi_CA(x) = phi_CB(x)+phi_BA_prime(x)

That is also the code recipe --- i'd suggest zeroes at the boundary.

B.