vndmtrx / js_astro

Sample code for astrological calculation written by JavaScript

js_astro

Sample code for astrological calculation written by JavaScript.

This library intent to:

• calculation of major planetary position(geocentric, apparent longitude) for 0-4000 A.D. within 1 arcminute.
• calculation of house cusp longitudes

Requirement

Environment

Newest Browser, but all comments are written in Japanese(Shift-JIS).

Library

Some functions requires spirntf.js, but if you don't want to use function cnv2*, not required.

License

Files in this repository are released under MIT license.

Usage

Calculate for planetary position

Include all libraries, and call calPlanetPositon2 as:

var planetPosition = new Array();
planetPosition = calPlanetPosition2( year, month, day, hour, minute, longitude, latitude );

calPlanetPosition2 returns array of 15 values:

• Julian day
• Planetary Position(Geocentric apparent ecliptic longitude): Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
• Lunar Node & apogee Longitude(from approximate osculate orbital elements)
• Longitude of Ascendant, MC(Mid heaven)
  • All value is expressed in degree, without Julian day.

Calculate for house cusp longitudes

Include all libraries, and call calHouseCusp2 as:

var cuspLongitudes = new Array();
cuspLongitudes = calHouseCusp2( year, month, day, hour, minute, longitude, latitude, 1 );

Last Argument 1 means Placidus house system.

calHouseCusp2 returns array of house cusp longitude(Index of this array starts 1, not 0).

Important notice

Timezone used in this library is Japan Standard Time(UTC+0900). You may consider to wrapper function to convert your local timezone. I never consider any Daylight Saving Time in past and future.

This library assumes eastern geographical longitude and northern geographical latitude as plus(eg. Tokyo: 139E42 = +139.70, 35N41 = +35.68).

Demonstration

To test this library, try this.

Errata for Leaflet written in Japanese

This library has a leaflet, and this leaflet has some error. Errata is here.