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Swiss Ephemeris binding for node.js

NOTE: Need help to mantain this project. Please write me.

About

Swiss Ephemeris binding for node.js.

Supported platforms: Mac OS X | Windows | Linux | FreeBSD

Getting started

To install run:

$ npm install swisseph

Requirements

From version 0.5.x only nodejs 0.12 or newer supported.

To use with older nodejs version use swisseph 0.4.x or older.

Version 0.5.x Notes

From version 0.5.x only nodejs 0.12 supported, because of C addons API compatibility.

Also, project splited to swisseph and swisseph-api.

swisseph responsible only for nodejs binding, but swisseph-api to access over the web.

Usage

Getting julian day

var swisseph = require ('swisseph');

var date = {year: 2015, month: 1, day: 1, hour: 0};

var julday = swisseph.swe_julday (date.year, date.month, date.day, date.hour, swisseph.SE_GREG_CAL);

Getting Sun and Moon position

Example:

var swisseph = require ('swisseph');

// Test date
var date = {year: 2012, month: 1, day: 1, hour: 0};
console.log ('Test date:', date);

var flag = swisseph.SEFLG_SPEED;

// path to ephemeris data
swisseph.swe_set_ephe_path (__dirname + '/../ephe');

// Julian day
swisseph.swe_julday (date.year, date.month, date.day, date.hour, swisseph.SE_GREG_CAL, function (julday_ut) {
	assert.equal (julday_ut, 2455927.5);
	console.log ('Julian UT day for date:', julday_ut);

	// Sun position
	swisseph.swe_calc_ut (julday_ut, swisseph.SE_SUN, flag, function (body) {
		assert (!body.error, body.error);
		console.log ('Sun position:', body);
	});

	// Moon position
	swisseph.swe_calc_ut (julday_ut, swisseph.SE_MOON, flag, function (body) {
		assert (!body.error, body.error);
		console.log ('Moon position:', body);
	});
});

For more examples see examples and test folders.

Using ecliptic, equatorial or rectangular coordinates

On computing planet, star, node or apside positions, and using SEFLG_EQUATORIAL or SEFLG_XYZ in flag bits, name of the resulting property will be different from the case with ecliptic coordinates. Run examples/issue-23.js in details, please.

Ephemeris settings

There are 3 different types of ephemeris supported:

Steve Moshier interpolation, covers 3000 BC – 3000 AD, preision 0.1 arcsec, no data files required.
Swiss Ephemeris is compressed version of DE431, covers 13000 BC - 17000 AD, precision 0.001 arcseconds, requires data files about 90MB. Download from ftp://www.astro.com/pub/swisseph/ephe.
JPL NASA ephemeris is the state of the art ephemeris, DE431 covers 13000 BC - 17000 AD, maximum possible precision, requires data files 2.9GB. Download from ftp://www.astro.com/pub/jplfiles.

To use data files download them and put in folder then set path to the ephemeris folder by:

swisseph.swe_set_ephe_path ('/path/to/downloaded/ephemeris');

And select ephemeris by setting the flag:

// for Moshier
body = swisseph.swe_calc_ut (julday_ut, swisseph.SE_SUN, swisseph.SEFLG_SPEED | swisseph.SEFLG_MOSEPH)

// for Swiss Ephemeris
body = swisseph.swe_calc_ut (julday_ut, swisseph.SE_SUN, swisseph.SEFLG_SPEED | swisseph.SEFLG_SWIEPH)

// for JPL NASA ephemeris
body = swisseph.swe_calc_ut (julday_ut, swisseph.SE_SUN, swisseph.SEFLG_SPEED | swisseph.SEFLG_JPLEPH)