Changelog#

Unreleased#

Changed#

  • HEALPix-facing public APIs now take the Grid4Earth level directly and derive nside = 2**level internally. This applies to HealPixConv, LargeConv, HealPixDown, HealPixUp, HEALPixSHT, localized ALM transforms, and build_healpix_adjacency.

Fixed#

  • HealPixConv geometry cache keys retain the input cell_ids order, so a permutation of the same partial domain cannot reuse incompatible sorting buffers.

Added#

  • HealPixResampler and resample_healpix: reusable and one-shot local resampling between full or partial NESTED HEALPix levels, with NaN support.

  • HealPixDivCurl and HealPixMultiScaleDivCurl: fixed gauge-aware derivative kernels for divergence and curl at every decomposition scale.

  • HealPixDecomp and HealPixPyramid: exactly reconstructing local Laplacian pyramids with cell identifiers retained at every scale.

  • HealPixFFTConv: differentiable, zero-padded FFT convolution for very large learned kernels on local pole-safe gnomonic HEALPix patches.

  • HEALPixSHT: ring-based full-sky spherical harmonic transform with spin support (spin-0, spin-1, spin-2)

  • alm_latlon: SHT for arbitrary iso-latitude grids (ERA5, regular lat/lon, HEALPix)

  • HealPixConv: gauge-equivariant spherical convolution on HEALPix maps

  • HealPixDown / HealPixUp: multi-resolution operators (smooth and max-pool modes)

  • powerspectra / powerspectra_lonlat: isotropic 1D power spectrum estimation

  • LocalizedFlatSkyAlm: flat-sky approximation for localized SHT on large patches