a radially symmetric spherical kernel represented by Legendre coefficients.

Syntax

psi = S2Kernel(A)
values = psi(np.cos(theta))

Description

The series is sum(A[n]*P_n(t)), with t=cos(theta) and P_n the Legendre polynomial. A[0] is the mean over the sphere under uniform probability. Arbitrary coefficients are neither rescaled to mean one nor constrained to give nonnegative values.

Use a kernel family for a specified smoothing profile, or S2KernelHandle for a callable formula. Spherical kernels describe directional density estimates and smoothing around orientation fibres.

Input

A one-dimensional real coefficient array, degrees zero through L

Output

psi S2Kernel

Properties

A Legendre coefficients through the stored bandwidth
bandwidth largest stored Legendre degree

See also

S2KernelHandle, S2DeLaValleePoussinKernel, fibreODF, calcDensity

Signature

S2Kernel(A)

MATLAB’s S2Kernel.S2Kernel

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/S2Kernel.S2Kernel_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.