This software provides an SQL (PostgreSQL) interface for several HEALPIX functions, which allows you to convert the ra,dec coordinates into Healpix IDs and back.

Author: Sergey Koposov and multiple HEALPIX authors (C) 2012-2020

Email: skoposov AT ed DOT ac DOT uk

Example:

wsdb=> select healpix_ang2ipix_nest(1024, 12., 25.);
 healpix_ang2ipix_nest
-----------------------
               5102321
(1 row)

wsdb=> select healpix_ang2ipix_ring(1024, 12., 25.);
 healpix_ang2ipix_ring
-----------------------
               3627144
(1 row)

wsdb=> select healpix_ipix2ang_nest(1024, 4323);
     healpix_ipix2ang_nest
--------------------------------
 {47.63671875,3.24700649515993}
(1 row)

wsdb=> select healpix_ipix2ang_ring(1024, 4323);
        healpix_ipix2ang_ring
-------------------------------------
 {359.021739130435,87.8983556468228}
(1 row)

Installation

Prerequisites

You may need to install the postgresql-development packages (postgres-server-dev or something like this) You will need a compiler

• Download the package
• Compile the code using simple make
• Please check that you have pg_config in your path
• Install the packge using make install
• Load the functions into PostgreSQL by doing

wsdb=> create extension pg_healpix; 

from the psql client