hydrodynamics.m

Basic hydrodynamics infrastructure provider that returns first derivative operators with respect to the sample coordinates using periodic boundary conditions; it returns finite-difference or Fourier differentiation matrices correctly normalised for the physical sample dimensions.

Syntax

    [Fx,Fy,Fz]=hydrodynamics(parameters)

Parameters

  parameters.dims    - dimensions of the sample (meters),
                       one, two, or three-element row
                       vector

  parameters.npts    - number of points in each dimension
                       of the sample, one, two, or three-
                       element row vector

  parameters.deriv   - {'fourier'} requests Fourier diffe-
                       rentiation matrices; {'period',n}
                       requests n-point central finite-
                       difference matrices with periodic
                       boundary conditions

Returns

  Fx, Fy, Fz         - derivative matrices, SI units

Examples

This function is used by imaging.m context in situations when spatial dynamics, such as diffusion and flow, is present in the sample.

Notes

Empty arrays are returned for inactive dimensions. 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].

See also

imaging.m, fdmat.m, v2fplanck.m, fourdif.m, corrfun.m, fdhess.m, fdkup.m, fdlap.m, fdvec.m, fdweights.m, fpl2phan.m, fpl2rho.m, g2fplanck.m, interpmat.m, mri_2d_plot.m, ngridpts.m, oscillator.m, overwound.m, phan2fpl.m, phantoms.m, qxspen_kernel.m, spden.m, Imaging_module, Kernel_utilities

Version 1.10, authors: Ahmed Allami, Ilya Kuprov