Powder.m

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Powder interface to pulse sequences. Generates a Liouvillian super- operator, the initial state and the coil state, then passes them on to the pulse sequence function.

This function supports parallel processing via Matlab's Distributed Computing Toolbox - different crystal orientations are evaluated on different labs. Arguments:

   pulse_sequence  -  pulse sequence function handle. See the
                      experiments directory for the list of
                      pulse sequences that ship with Spinach.

   parameters      -  a structure containing sequence-specific
                      parameters. See the pulse sequence header
                      for the list of parameters each sequence
                      requires. The parameters that this inter-
                      face itself requires are:
                     
                      parameters.spins - a cell array giving the
                      spins that the pulse sequence works on, in
                      the order of channels, e.g. {'1H','13C'}
                      parameters.offset - a cell array giving
                      transmitter offsets on each of the spins
                      listed in parameters.spins.
                      parameters.grid - name of the spherical 
                      averaging grid file (see the grids direc-
                      tory in the kernel).
   assumptions     -  context-specific assumptions ('nmr', 'epr',
                      'labframe', etc.) - see the pulse sequence
                      header for information on this setting.

This function returns a powder average of whatever it is that the pul- se sequence returns. If a structure is returned by the pulse sequence, the structures are powder averaged field-by-field.