Difference between revisions of "G2fplanck.m"

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{{DISPLAYTITLE:g2fplanck.m}} __NOTOC__
 
{{DISPLAYTITLE:g2fplanck.m}} __NOTOC__
Returns magnetic field gradient operators within the Fokker-Planck formalism used in the imaging module of ''Spinach''.
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Returns the magnetic field gradient operators used by the imaging module within the Fokker-Planck formalism; the output cell array contains {Gx,Gy,Gz}, which should be added to the Hamiltonian with appropriate coefficients, and gradients are assumed linear and centred on the middle of the sample.
 
 
The cell array contains {Gx,Gy,Gz}, which should simply be added to the Hamiltonian with appropriate coefficients. Gradients are assumed to be linear and centered on the middle of the sample.
 
  
 
==Syntax==
 
==Syntax==
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==See also==
 
==See also==
[[v2fplanck.m]], [[hydrodynamics.m]], [[imaging.m]]
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[[v2fplanck.m]], [[hydrodynamics.m]], [[imaging.m]], [[polyadic/inflate.m]], [[mri_2d_plot.m]], [[ngridpts.m]], [[phantoms.m]], [[Imaging_module]]
  
 
''Version 2.1, authors: [[Ilya Kuprov]], [[Ahmed Allami]]''
 
''Version 2.1, authors: [[Ilya Kuprov]], [[Ahmed Allami]]''

Latest revision as of 19:36, 6 June 2026

Returns the magnetic field gradient operators used by the imaging module within the Fokker-Planck formalism; the output cell array contains {Gx,Gy,Gz}, which should be added to the Hamiltonian with appropriate coefficients, and gradients are assumed linear and centred on the middle of the sample.

Syntax

    G=g2fplanck(spin_system,parameters)

Parameters

  parameters.dims    - a vector with one, two or three 
                       elements giving the dimensions
                       of the box, metres

  parameters.npts    - a vector with one, two or three
                       elements giving number of points
                       in each dimension of the box

Outputs

  G - a cell array with the three gradient operators 
      ordered as {Gx,Gy,Gz}, normalised to 1 T/m, empty
      matrices for non-exitent dimensions

Notes

1. The direct product order is Z(x)Y(x)X(x)Spin, this corresponds to a column-wise vectorization of a 3D array with dimensions ordered as [X Y Z].

2. Polyadic objects are returned, use polyadic/inflate.m to get the corresponding sparse matrix.

See also

v2fplanck.m, hydrodynamics.m, imaging.m, polyadic/inflate.m, mri_2d_plot.m, ngridpts.m, phantoms.m, Imaging_module

Version 2.1, authors: Ilya Kuprov, Ahmed Allami