Rotframe.m

Rotating frame transformation with respect to a specified group of spins to specified order in perturbation theory. Syntax:

         H=rotframe(spin_system,C,H,isotope,order)


Parameters:

   C      - carrier Hamiltonian with respect to which the
rotating frame transformation is to be done

   H      - laboratory frame Hamiltonian H0+H1 that is to
be transformed into the rotating frame

   isotope - string, such as '1H', specifying the spins
with respect to which the transformation is
being computed

   order   - perturbation theory order in the rotating
frame transformation