Author: Generative AI (Academic Compilation) Date: April 14, 2026 Subject: Jyotish (Vedic Astrology) – Padakrama Sahita Abstract Arudha Lagna (AL), also known as the Pada Lagna , is a crucial yet often misunderstood concept in Parashari Vedic astrology. Unlike the natal Lagna (Ascendant), which represents the physical self, Arudha Lagna signifies the image , illusion , or worldly perception of the self—how the world sees the native. This paper presents a formal algorithm for an Arudha Lagna calculator, detailing step-by-step computation rules, edge cases (e.g., 7th house exceptions), and interpretive frameworks. We provide pseudo-code, verification examples, and a discussion of common errors in software implementation. 1. Introduction In classical Jyotish, the Bhavat Bhavam principle teaches that houses derive meaning from their relationship to other houses. Arudha (literally "mounted" or "vehicle") takes this further: it is the reflection of a house’s owner or signification onto another house. Specifically, Arudha Lagna is the reflection of the Ascendant (Lagna) itself.
If ( AL_pre = H_L ) (i.e., AL falls in Lagna itself), then AL is 10th house from Lagna . If ( AL_pre ) is exactly the 7th house from Lagna, then AL is 4th house from Lagna . 3. Algorithm for an Arudha Lagna Calculator The following pseudo-code implements the classic Parashari rule. 3.1 Pseudo-code function calculate_arudha_lagna(lagna_degrees, house_positions_of_planets): # lagna_degrees: 0-360 # house_positions: dict planet: house_number 1..12 # 1. Find Lagna sign and its lord lagna_sign = floor(lagna_degrees / 30) + 1 # 1=Aries ... 12=Pisces lord_of_lagna = get_planet_ruler(lagna_sign) # e.g., Mars for Aries arudha lagna calculator
Exception: AL_pre == Lagna (1) → final AL = 10th house. Author: Generative AI (Academic Compilation) Date: April 14,
Let ( LordPos ) = house of Lagna lord (1..12). Let ( LagnaHouse = 1 ). ( D = ((1 - LordPos) \mod 12) ); if ( D == 0 ), ( D = 12 ). ( AL_pre = ((LordPos - 1 + D) \mod 12) + 1 ). If ( AL_pre == 1 ): ( AL = 10 ). Else if ( AL_pre == 7 ): ( AL = 4 ). Else ( AL = AL_pre ). End of paper. This paper can be used as both a theoretical introduction and a developer’s specification for building an accurate Arudha Lagna calculator. if ( D == 0 )