math/ssht 1.5.2 DragonFly

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 the forward, inverse and inverse adjoint transforms.

In some applications adjoint forward and inverse spherical harmonic transforms are also required (for example, when solving convex optimisation problems). Functionality is also provided to perform fast and exact adjoint transforms, based on the fast algorithms derived in McEwen et al. (2013).