Switch to using WCSLIB for HEALPIX about reproject HOT 3 CLOSED

Thanks Tom, I fully agree that if we can get the functionality we need from WCSLib or by implementing some things ourselves, without the HEALPIX dependency, it's worth some effort.

Side comment – Even after reading about HEALPIX a bit (e.g. at https://en.wikipedia.org/wiki/HEALPix, or the HEALPIX and WCSLib pages), I'm still confused. If someone has the time to write a more hands-on / software-oriented tutorial introduction to HEALPIX, i.e. what is in WCSLib / astropy.wcs and what is in HEALPIX / healpy and give simple examples of HEALPIX FITS files ... I would find this hugely helpful and I suspect other astronomers that only need to work with HEALPIX rarely and want to grok it and know how to work with it in ~ 1 hour would do too.

from reproject.

At the moment, this is a command-line utility in WCSLIB so we'd need that functionality to be moved to the library. I've asked Mark if this would be possible.

I got a positive reply from Mark, and he will look into it!

@cdeil - I agree, it would be nice to have a simpler description of the HEALPIX algorithm (I don't understand all the details myself)

from reproject.

No longer an issue anymore now that we use astropy-healpix (https://github.com/astrofrog/reproject/pull/139)

from reproject.