# g2fplanck.m

From Spinach Documentation Wiki

Returns magnetic field gradient operators within the Fokker-Planck formalism used in the imaging module of *Spinach*.

## Syntax

G=g2fplanck(spin_system,parameters)

## Description

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.

## Arguments

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

*Version 2.1, authors: Ilya Kuprov, Ahmed Allami*