astronomical-almanac-js

This is the port to asm.js of Debian's astronomical-almanac.

The original license is GPL v2.0 and is found in the debian/copyright file. This package is licensed under the same licence.

The original README is the readme.404 file in the main directory.

The changes made are:

• The makefile generates JavaScript targets using emcc and modified CFLAGS
• Added planet.js and planet-node.js targets. They wrap the algorithm that computes the distance between two planets. planet.js can be used in the browser using Module.cwrap and planet-node.js can be used from the command line.

All programs compile but the only one guaranteed to work is the new planet.js library and the planet-node.js standalone program.

Building

$ npm install
$ make clean
$ make -j  # or just make

The distance algorithm is embedded in planet.js, planet.js.mem and planet.js.symbols for browser based projects. You'll need planet-node.js, planet-node.js.mem and planet-node.js.symbols for running it from the command line.

Examples

In the browser

<script type="text/javascript" src="planet.js"></script>

var kmToPlanet = Module().cwrap("km_to_planet", "number", ["number", "number"]);
var now = new Date().getTime() / 86400000 + 2440587.5; // Julian day
console.log(kmToPlanet(now, 4)); // Earth to Mars

A live example: http://connettiva.eu/newton (source at newton-says)

From the command line

$ node planet-node.js $(node julian_day.js) 4  # Earth to Mars

Available planet numbers

• 1 Mercury
• 2 Venus
• 4 Mars
• 5 Jupiter
• 6 Saturn
• 7 Uranus
• 8 Neptune
• 9 Pluto