interpolate sampled spherical data linearly over a triangulation.

Syntax

f = S2FunTri(directions, values)
f = S2FunTri(triangulation, values)
f = S2FunTri(lambda v: v.z**2)

Description

The value within a spherical triangle is the barycentric interpolation of its three vertex values. Duplicate directions are merged and their values averaged. Passing a callable samples it on a grid of 1.5 degrees before constructing the triangulation. The result can be evaluated with f(queryDirections).

This representation stores sample values rather than harmonic coefficients. Products, powers and pointwise transforms operate at the vertices and interpolate the transformed values between them. They can differ from applying the same transform after interpolation.

Input

nodes vector3d directions, S2Triangulation, or a vectorised callable of directions
values one row of sampled values per node; several columns represent several functions

Output

f S2FunTri

Properties

vertices unit directions of the triangulation
values numeric array with one row per vertex and one column per function
tri S2Triangulation defining the face connectivity
frame reference frame carried by the vertices

See also

vector3d.interp, S2FunHarmonic, S2Triangulation

Signature

S2FunTri(nodes, values=None)

MATLAB’s S2FunTri.S2FunTri

source

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/S2FunTri.S2FunTri_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.