SHTOOLS is a Fortran-95 library that can be used for spherical harmonic transforms, multitaper spectral analyses, expansions of gridded data into Slepian basis functions, and standard operations on global gravitational and magnetic field data.
- Supports all standard normalizations and phase conventions of the spherical harmonic functions.
- Use of both regularly sampled geographic grids and grids appropriate for Gauss-Legendre quadrature.
- Spherical harmonic transforms proven to be accurate up to about degree 2800.
- Perform localized multitaper spectral analyses, or expand gridded data in terms of localized Slepian basis functions.
- Perform basic operations on global gravity and magnetic field data.
- OpenMP compatible and OpenMP thread-safe versions of the Fortran routines.
To call the SHTOOLS routines from within a Fortran 95 program, you will need to place the command
use SHTOOLS
immediately after the program/subroutine/function name. To compile the program, it will be necessary to link to LAPACK, BLAS, and FFTW3 compatible libraries.
The SHTOOLS software package is entirely free and open source. It can be modified and distributed according to the 3-clause BSD license.