S2LET

"The S2LET code provides high performance routines for fast wavelet analysis of signals on the sphere. It uses the SSHT code built on the MW sampling theorem to perform exact spherical harmonic transforms on the sphere. The SO3 code is also needed for the exact Wigner transform on the rotation group. The resulting wavelet transform is theoretically exact, i.e. a band-limited signal can be recovered from its wavelet coefficients exactly and the wavelet coefficients capture all the information. S2LET also supports the HEALPix sampling scheme, in which case the transforms are not theoretically exact but achieve good numerical accuracy.

S2LET supports scale-discretised axisymmetric wavelets (Wiaux et al 2008, Leisted et al 2012), directional wavelets (McEwen et al 2015), ridgelets (McEwen 2015), and curvelets (Chan et al 2017), as well as needlets (Marinucci et al 2008, Baldi et al 2006) and B-spline wavelets (Starck et al 2006). It exploits a fast Wigner transform on the rotation group (implemented in SO3) to perform the scale-discretised wavelet transform, which anyalyses of scalar and spin signals are both supported.

This page outlines the main features of the code, installation details as well as the core functionalties and interfaces. References, version, and license information then follows. S2LET requires the SSHT, SO3, and FFTW libraries. The IO FITS features require CFITSIO. To support HEALPix, a valid installation of its Fortran implementation must be provided. More details about an installation from scratch can be found on the Dependencies page."

http://astro-informatics.github.io/s2let/

https://arxiv.org/abs/1508.05406

https://arxiv.org/abs/1612.08062

https://arxiv.org/abs/1211.1680