Libpsht - algorithms for efficient spherical harmonic transforms

TL;DR

Libpsht is a portable, efficient C90 library providing algorithms for fast spherical harmonic transforms supporting various pixelisations and hardware acceleration, optimized for astronomical data analysis.

Contribution

It introduces a highly efficient, portable library for spherical harmonic transforms supporting multiple pixelisations and hardware features, with broad language integration.

Findings

Among the most efficient algorithms in the astronomical community

Supports multiple pixelisations like HEALPix, GLESP, and ECP

Optimized for multi-core and vectorized hardware

Abstract

Libpsht (or "library for Performant Spherical Harmonic Transforms") is a collection of algorithms for efficient conversion between spatial-domain and spectral-domain representations of data defined on the sphere. The package supports transforms of scalars as well as spin-1 and spin-2 quantities, and can be used for a wide range of pixelisations (including HEALPix, GLESP and ECP). It will take advantage of hardware features like multiple processor cores and floating-point vector operations, if available. Even without this additional acceleration, the employed algorithms are among the most efficient (in terms of CPU time as well as memory consumption) currently being used in the astronomical community. The library is written in strictly standard-conforming C90, ensuring portability to many different hard- and software platforms, and allowing straightforward integration with codes written in various programming languages like C, C++, Fortran, Python etc. Libpsht is distributed under the terms of the GNU General Public License (GPL) version 2 and can be downloaded from http://sourceforge.net/projects/libpsht.