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Fokker-Planck magic angle spinning context. Generates a Liouvillian superoperator and passes it on to the pulse sequence function, which should be supplied as a handle. Syntax:


where pulse sequence is a function handle to one of the pulse sequences located in the experiments directory, assumptions is a string that would be passed to assume.m when the Hamiltonian is built and parameters is a structure with the following subfields:

    parameters.rate     - spinning rate in Hz
    parameters.axis     - spinning axis, given as a normalized
                          3-element vector
    parameters.spins    - a cell array giving the spins that 
                          the pulse sequence involves, e.g. 
    parameters.offset   - a cell array giving transmitter off-
                          sets in Hz on each of the spins listed
                          in parameters.spins array
    parameters.max_rank - maximum harmonic rank to retain in
                          the solution (increase till conver-
                          gence is achieved, approximately
                          equal to the number of spinning si-
                          debands in the spectrum)
    parameters.rframes  - rotating frame specification, e.g.
                          {{'13C',2},{'14N',3}} requests second
                          order rotating frame transformation
                          with respect to carbon-13 and third
                          order rotating frame transformation
                          with respect to nitrogen-14. When
                          this option is used, the assumptions
                          on the respective spins should be
                          laboratory frame.
    parameters.grid     - spherical grid file name. See grids
                          directory in the kernel.
    parameters.sum_up   - when set to 1 (default), returns the
                          powder average. When set to 0, returns
                          individual answers for each point in 
                          the powder as a cell array.

Additional subfields may be required by the pulse sequence. The parameters structure is passed to the pulse sequence with the following additional parameters set:

  parameters.spc_dim  - matrix dimension for the spatial
                        dynamics subspace
  parameters.spn_dim  - matrix dimension for the spin 
                        dynamics subspace

This function returns the powder average of whatever it is that the pulse sequence returns.

Note: arbitrary order rotating frame transformation is supported, including infinite order. See rotframe.m for further information.