PURIFY provides functionality to perform radio interferometric imaging, i.e. to recover images from the Fourier measurements taken by radio interferometric telescopes. PURIFY leverages recent developments in the field of compressive sensing and convex optimisation, adapted, in some cases extended, and applied to radio interferometric imaging.
PURIFY itself contains functionality specific to radio interferometry, whereas all sparse optimisation functionality is implemented in the companion code SOPT. SOPT provides very general algorithms for solving sparse regularisation problems and is being applied in many areas become radio interferometry.
S2BALL is a JAX package for computing the scale-discretised wavelet transform on the ball and rotational ball. It leverages autodiff to provide differentiable transforms, which are also deployable on modern hardware accelerators (e.g. GPUs and TPUs).
The transforms S2BALL provides are optimally fast but come with a substantial memory overhead and cannot be used above a harmonic bandlimit of L ~ 256, at least with current GPU memory limitations. That being said, many applications are more than comfortable at these resolutions, for which these JAX transforms are ideally suited, e.
S2CONV is a Python package implementing the generalised lifted spherical convolution and the spherical convolutions it unifies, for scalar fields, spin fields and functions on the rotation group, using JAX. All operators are differentiable, deployable on hardware accelerators (e.g. GPUs and TPUs), and exact for band-limited signals, leveraging the differentiable and accelerated spherical harmonic and Wigner transforms implemented in S2FFT. The generalised lifted convolution, introduced in Unifying spherical convolutions through lifting, recovers axisymmetric, directional, group, spin-changing and steerable convolutions, among others, as special cases that differ only in their kernels.
S2FFT is a JAX package for computing Fourier transforms on the sphere and rotation group. It leverages autodiff to provide differentiable transforms, which are also deployable on modern hardware accelerators (e.g. GPUs and TPUs).
More specifically, S2FFT provides support for spin spherical harmonic and Wigner transforms (for both real and complex signals), with support for adjoint transformations where needed, and comes with different optimisations (precompute or not) that one may select depending on available resources and desired angular resolution.