About this package

This is a BSD-licensed Python package for HEALPix, which is based on the C HEALPix code written by Dustin Lang originally in astrometry.net, and was added here with a Cython wrapper and expanded with a Python interface.

The healpy package that is a wrapper around the HEALPix C++ library has existed for a long time. So why this re-write?

The main motivation is that the original HEALPIX/healpy packages are GPL-licensed, which is incompatible with the BSD license used by Astropy and most Astropy-affiliated and scientific Python (Numpy, Scipy, …) package, and HEALPix/healpy will not be relicensed (see here). In addition, the present package doesn’t have a big C++ package as a dependency, just a little C and Cython code, which makes it easy to install everywhere – we support Linux, MacOS X, and Windows.

However, this package is intended to be lightweight and we do not plan to fully implement everything that healpy and the original HEALPix library support (such as spherical harmonics).

Note that code contributions to this package can’t be derived from the HEALPix package or healpy due to licensing reasons (see above).