Trikona Shodhana

Definition

Trikona Shodhana — the trinal or triangular reduction — is the first of two reductions applied to an Ashtakavarga before you use the figures to judge longevity or transits. Once the chart of dots is built for every planet and the Ascendant, you take the twelve signs in their four trine groups of three equidistant signs, and within each group subtract the least figure from all three, so the lowest becomes zero. If a sign in a group has no dots, you make no reduction; the Ekadhipatya Shodhana follows.

In Tradition

Across classical and modern Jyotish writing, Trikona Shodhana is read as the first of the two Ashtakavarga reductions, done before the Ekadhipatya Shodhana to refine the raw benefic figures before judgement. Inside each trine group, the sign holding the fewest dots governs how the other two are cut; where a sign in the group holds none, the figures are left untouched.

In Practice

A jyotishi runs Trikona Shodhana on each planet's Ashtakavarga, and on the Ascendant's, as the opening step of the reduction sequence that readies the figures for longevity and transit judgement, with the Ekadhipatya Shodhana following. The classical sources differ on the exact operation. The Brihat Parashara Hora Shastra, in Kapoor's rendering, subtracts the least figure of a trine from all three so the lowest becomes zero, except where a sign already holds no dots. The Jataka Parijata, in Sastri's rendering, gives both this subtractive method and the Balabhadra school current in Southern India, which instead reduces the other two figures down to the least; either way, when all three figures are equal they are all removed. Raman likewise notes two classical interpretations of the reduction and adopts the subtractive one.

Historical Origin

Trikona Shodhana is attested in the classical Sanskrit texts: in the Brihat Parashara Hora Shastra (Ch.67) of Maharshi Parasara, quoted here in Gouri Shankar Kapoor's translation, and in the Jataka Parijata (Ch.10) of Vaidyanatha Dikshita, in V. Subramanya Sastri's translation. The modern author Raman expounds it too.

Further Reading

• Maharshi Parasara, Brihat Parashara Hora Shastra
• Vaidyanatha Dikshita, Jataka Parijata
• B.V. Raman, Hindu Predictive Astrology