The SSHT code provides functionality to perform fast and exact spin spherical harmonic transforms based on the sampling theorem on the sphere derived in McEwen & Wiaux (2011).

SSHT can also interface with ducc0 and use it as a backend for spherical harmonic transforms and rotations.

The python package, pyssht, is available on pypi and can be installed with:

pip install pyssht

The C package can be installed with CMake and conan.

Both can be installed using pip:

pip install conan cmake

Then SSHT can be compiled with:

git clone https://github.com/astro-informatics/ssht.git
mkdir ssht/build && cd ssht/build
cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr/local -Dconan_deps=True ..
make
make install

The above will also download FFTW, if necessary.

Further instructions for installing SSHT Matlab and Fortran versions are available here.

Further documentation is available here.

Usage for the python package is also given in the package docstring.

If you use SSHT for work that results in publication, please reference https://github.com/astro-informatics/ssht/ and cite our related academic papers:

• J. D. McEwen and Y. Wiaux, A novel sampling theorem on the sphere, IEEE Trans. Sig. Proc., 59(12):5876-5887, 2011 (arXiv:1110.6298).
• J. D. McEwen, G. Puy, J.-Ph. Thiran, P. Vandergheynst, D. Van De Ville, and Y. Wiaux, Sparse image reconstruction on the sphere: implications of a new sampling theorem. IEEE Trans. Image Proc., 22(6):2275-2285, 2013 (arXiv:1205.1013).

SSHT is released under the GPL-3 license. For further details see LICENSE.

SSHT was initially written by Jason McEwen but significant contributors have since been made by a number of others.