Yoga detection: Raja yogas and more

Five combinations formed when Mars, Mercury, Jupiter, Venus or Saturn sits in its own sign or exaltation and occupies an angle from the ascendant. They are named Ruchaka, Bhadra, Hamsa, Malavya and Shasha.

Around forty named rules, covering the five panchamahapurusha yogas, raja and dhana yogas including the viparita and neecha bhanga cases, the lunar and solar combinations such as Gajakesari, Sunapha and Budha Aditya, sign exchanges, the Nabhasa figure, and the combinations usually treated as calling for care. Rules that can fire more than once, such as raja yogas, are reported once per instance.

The lord of an angle and the lord of a trine acting together, by sharing a sign, by exchanging signs, or by aspect. The angles are the 1st, 4th, 7th and 10th houses, the trines the 1st, 5th and 9th. They are common: several planets in one sign will form a handful at once, which is why this calculator names the two lords involved rather than just reporting that one exists.

Kala Sarpa is not in the classical corpus. It appears in twentieth century Indian astrological writing and became widely known through the remedies sold against it. A single planet outside the arc between Rahu and Ketu breaks it entirely. This calculator reports it because leaving a result out is worse than explaining it, and gives the conditions under which authorities set it aside.