SHTOOLS/pyshtools is extremely versatile:
All standard normalizations of the spherical harmonic functions are supported: 4π normalized, Schmidt semi-normalized, orthonormalized, and unnormalized.
Both real and complex spherical harmonics are supported, and one can choose to either use or exclude the Condon-Shortley phase factor of (-1)m.
Spherical harmonic transforms are calculated by exact quadrature rules using either the sampling theorem of Driscoll and Healy (1994) or Gauss-Legendre quadrature.
The spherical harmonic transforms are fast and accurate to approximately degree 2800.
Localized multitaper spectral analyses and expansions of functions in localized Slepian bases are easily performed.
Standard operations on global gravitational and magnetic field data are supported.
The Fortran routines are OpenMP compatible and OpenMP thread-safe.
The Python components of SHTOOLS can be installed using the Python package manager
pip. Binaries are pre-built for linux and macOS architectures, and you need only to execute the following command in a unix terminal:
pip install pyshtools
To upgrade a pre-existing installation use
pip install --upgrade pyshtools
To install the Fortran 95 components for use in your Fortran programs, execute the following command in the SHTOOLS directory
make fortran make fortran-mp # for OpenMP
or alternatively install using the brew package manager (macOS)
brew tap shtools/shtools brew install shtools
SHTOOLS/pyshtools can be called from any Fortran 95 or Python program. The core software is written in Fortran 95, and Python wrappers allow simple access to the fortran-compiled routines. A variety of Python notebooks and example files are included that demonstrate the major features of the library. When building from source, it will be necessary to link to LAPACK, BLAS, and FFTW compatible libraries. SHTOOLS is open source software (3-clause BSD license).
Mark A. Wieczorek and Matthias Meschede (2018). SHTools — Tools for working with spherical harmonics, Geochemistry, Geophysics, Geosystems, 19, 2574-2592, doi:10.1029/2018GC007529.Edit me