Grids and triangulations for sampling directions and rotations, and for finding nearby samples.

Class or function Description
S1Grid a sorted list of angles on an interval [min, max], periodic or not, the nearest neighbour and radius search of the tensor product grids S2Grid and SO3Grid
S2Grid a grid on the sphere with ring structure, a ladder of polar angles theta and one azimuth grid per ring, whose nearest and radius searches use that structure
S2Triangulation the Delaunay triangulation of directions on the sphere, their convex hull: the triangles T, counterclockwise from outside, and the triangle opposite each vertex
SO3Grid the equispaced grid of orientations over one fundamental region of its frame pair, MATLAB’s SO3Grid: an S2 grid of the images of z with a ladder of gamma per node, so a search costs three binary searches
fibonacciS2Grid the spherical Fibonacci grid: N = 2n + 1 points along a spiral, z linear in the index and the azimuth advancing by the golden angle
quadratureS2Grid nodes and surface-area weights for integrating functions on the unit sphere
fibonacciSO3Grid a low discrepancy grid of orientations from a super-Fibonacci spiral, restricted to the fundamental region of the frame pair
quadratureSO3Grid the quadrature grid on SO(3) of a bandwidth: the nodes and weights that integrate every harmonic function up to that degree exactly
HEALPixS2Grid the HEALPix nodes of the sphere as a list of directions
SO3FibonacciGrid the super-Fibonacci grid of orientations, a low-discrepancy quaternion spiral trimmed to one fundamental region of the frame pair, searched through the quaternion k-d tree
equispacedS2Grid an equispaced spherical grid, nearly equidistant directions on rings of constant polar angle
regularS2Grid a regular spherical grid, the tensor product of a ladder of polar angles and a ladder of azimuths, the layout of pole figure files
equispacedSO3Grid nearly equidistant orientations covering one fundamental region of the frame pair
regularSO3Grid the regular raster of Euler angles over the Euler box of the frames, as the ODF sections show it
superfibonacciSO3Grid a super-Fibonacci grid of orientations covering one fundamental region of the frame pair, its resolution the mean spacing of nearest neighbours
localOrientationGrid an equispaced grid of orientations in a ball about a centre
localS2Grid an equispaced grid of directions in a spherical cap about a centre

Citing this page. This page is part of the documentation of MTEX, a free and open source MATLAB toolbox for analyzing and modeling crystallographic textures. It was written by The MTEX Developers and is published at https://mtex-toolbox.github.io/geometryGrids_index_py.html. If you use MTEX, or reuse text or figures from this page, in your research, please cite

F. Bachmann, R. Hielscher, H. Schaeben: Texture Analysis with MTEX - Free and Open Source Software Toolbox, Solid State Phenomena 160 (2010), 63-68. 10.4028/www.scientific.net/SSP.160.63

BibTeX
@article{bachmann2010mtex,
  author  = {F. Bachmann and R. Hielscher and H. Schaeben},
  title   = {Texture Analysis with MTEX - Free and Open Source Software Toolbox},
  journal = {Solid State Phenomena},
  volume  = {160},
  pages   = {63-68},
  year    = {2010},
  doi     = {10.4028/www.scientific.net/SSP.160.63},
  url     = {https://doi.org/10.4028/www.scientific.net/SSP.160.63}
}

Other papers describing specific MTEX methods are listed under Publications — please cite the one that best fits your application. The MTEX source code is licensed under the GNU General Public License v2.0; the text and figures of this documentation are licensed under CC BY 4.0, which permits reuse — including by automated systems — provided The MTEX Developers and this page are credited.