The mathematical conversion from Equatorial to Ecliptic is effectuated by the equation for the Ascendant, Lagna = arctan ( Sin E / Cos E Cos w – Sin w Tan A ) where Lagna is the Lagna on the Ecliptic and E is the Lagna on the Celestial Equator, the Sayana Kala Lagna. The Sayana Kala Lagna, E, is reduced to the Ecliptic by this equation. The Lagna is the intersecting point between the Eastern Celestial Horizon, the Kshitija with the Ecliptic.