vedic_jyotish_completion - TheDaniel166/moira GitHub Wiki

Vedic Jyotish Systems β€” Pre-Phase 1 Implementation Roadmap

Codebase State (Verified)

Present and usable:

  • moira/sidereal.py β€” tropical_to_sidereal, nakshatra_of, Ayanamsa, NAKSHATRA_LORDS
  • moira/varga.py β€” calculate_varga, wrappers for D7, D9, D10, D12, D30 only
  • moira/dasha.py β€” Vimshottari only; no alternative systems
  • moira/decanates.py β€” D3 via vedic_drekkana()
  • moira/dignities.py β€” Western only; nothing Vedic
  • moira/cycles.py β€” _jd_to_weekday(), planetary_day_ruler() available
  • moira/chart.py β€” ChartContext.planets, .nodes, .houses, .jd_ut, .is_day

None of the 7 target systems exist in any form.

Implementation Sequence (Dependency Order)

1. Shodashvarga Completion (varga.py extension)   β€” no upstream deps
2. Vedic Planetary Dignities (new module)          β€” no upstream deps
3. Jaimini Karakas (new module)                    β€” sidereal.py only
4. Panchanga (new module)                          β€” sidereal.py, cycles.py
5. Alternative Dasha Systems (new module)          β€” sidereal.py, dasha.py patterns
6. Ashtakavarga (new module)                       β€” vedic_dignities.py (for Shodhana)
7. Shadbala (new module)                           β€” all of the above

Rationale: Shadbala is the most downstream β€” Saptavargaja Bala requires all 7 varga sign positions, Kala Bala requires Panchanga elements (Vara, Paksha, Hora), and Drig Bala optionally uses Ashtakavarga scores. Everything else is self-contained.

System 1 β€” Shodashvarga Completion

Primary Authority

Parashara, Brihat Parashara Hora Shastra, Shodashavarga Adhyaya (Ch. 6–22).

Validation Reference

Jhora (Jagannatha Hora), Parashara Light 9.x; B.V. Raman, How to Judge a Horoscope.

File

Extend moira/varga.py.

Missing Wrappers

D2, D4, D6, D8, D16, D20, D24, D27, D40, D45, D60.

Non-Generic Parashari Rules

Varga Rule
D2 Hora Odd signs: 1st half (0°–15Β°) β†’ Leo, 2nd half β†’ Cancer. Even signs reversed.
D4 Chaturthamsha d4_sign = (sign_idx + segment_in_sign) % 12 β€” starts from own sign, not Aries.
D27 Saptavimshamsha Start from Aries (fire), Cancer (earth), Libra (air), Capricorn (water).
D40 Khavedamsha Odd signs start Aries; even signs start Libra.
D45 Akshavedamsha Odd signs start Aries; even signs start Capricorn.

Remaining (D6, D8, D16, D20, D24, D60): generic calculate_varga(lon, n).

Critical: The existing calculate_varga(lon, 4) does not match Parashari D4. The chaturthamsha() wrapper must use the sign-offset formula, not the generic call.

Key Formulas

# D2 Hora
sign_idx = int(sidereal_lon // 30)
deg_in_sign = sidereal_lon % 30
half = 0 if deg_in_sign < 15 else 1
is_odd_sign = (sign_idx % 2 == 0)   # 0-based: Aries=0 is 1st (odd) sign
if is_odd_sign:
    hora_sign = 4 if half == 0 else 3    # Leo(4) or Cancer(3)
else:
    hora_sign = 3 if half == 0 else 4    # Cancer(3) or Leo(4)

# D4 Chaturthamsha
segment_within_sign = int((sidereal_lon % 30) / 7.5)   # 0–3
d4_sign = (sign_idx + segment_within_sign) % 12

# D27 Saptavimshamsha
TRIPLICITY_START = {"fire": 0, "earth": 3, "air": 6, "water": 9}
SIGN_ELEMENT = ["fire","earth","air","water"] * 3   # Aries→Pisces
start = TRIPLICITY_START[SIGN_ELEMENT[sign_idx]]
segment = int((sidereal_lon % 30) / (30/27))
d27_sign = (start + segment) % 12

# D40 Khavedamsha
seg_40 = int((sidereal_lon % 30) / 0.75)
start_40 = 0 if (sign_idx % 2 == 0) else 6      # Aries or Libra
d40_sign = (start_40 + seg_40) % 12

# D45 Akshavedamsha
seg_45 = int((sidereal_lon % 30) / (30/45))
start_45 = 0 if (sign_idx % 2 == 0) else 9      # Aries or Capricorn
d45_sign = (start_45 + seg_45) % 12

Proposed Public Surface (additions to varga.py)

def hora(sidereal_longitude: float) -> VargaPoint: ...             # D2
def chaturthamsha(sidereal_longitude: float) -> VargaPoint: ...    # D4
def shashthamsha(sidereal_longitude: float) -> VargaPoint: ...     # D6
def ashtamsha(sidereal_longitude: float) -> VargaPoint: ...        # D8
def shodashamsha(sidereal_longitude: float) -> VargaPoint: ...     # D16
def vimshamsha(sidereal_longitude: float) -> VargaPoint: ...       # D20
def chaturvimshamsha(sidereal_longitude: float) -> VargaPoint: ... # D24
def saptavimshamsha(sidereal_longitude: float) -> VargaPoint: ...  # D27
def khavedamsha(sidereal_longitude: float) -> VargaPoint: ...      # D40
def akshavedamsha(sidereal_longitude: float) -> VargaPoint: ...    # D45
def shashtiamsha(sidereal_longitude: float) -> VargaPoint: ...     # D60

Tricky Edge Cases

  • sign_idx % 2 == 0 means "odd sign" in 0-based indexing (Aries=0 is the 1st, which is odd). This is counterintuitive β€” document clearly.
  • D60 sign assignment is generic; the optional named Shashtiamsha lords (60 traditional names from BPHS) are future enrichment.
  • Use int(lon % 30 // (30/n)) not rounding at segment boundaries.

Estimated Complexity

Moderate. Most wrappers are trivial; D2/D4/D27/D40/D45 require careful offset arithmetic and Jhora spot-checks.

System 2 β€” Vedic Planetary Dignities

Primary Authority

Parashara, BPHS Ch. 3, 26, 28. Kalyana Varma, Saravali Ch. 5–6.

Validation Reference

Jhora (dignity display + Panchadha Maitri grid); Raman, A Manual of Hindu Astrology.

File

moira/vedic_dignities.py

Exaltation and Debilitation

Planet Exaltation Deepest degree Debilitation
Sun Aries 10Β° Libra
Moon Taurus 3Β° Scorpio
Mars Capricorn 28Β° Cancer
Mercury Virgo 15Β° Pisces
Jupiter Cancer 5Β° Capricorn
Venus Pisces 27Β° Virgo
Saturn Libra 20Β° Aries

Mulatrikona Ranges

Planet Sign Range
Sun Leo 0°–20Β°
Moon Taurus 3°–30Β°
Mars Aries 0°–12Β°
Mercury Virgo 15°–20Β°
Jupiter Sagittarius 0°–10Β°
Venus Libra 0°–15Β°
Saturn Aquarius 0°–20Β°

Dignity Rank Order

Exaltation > Mulatrikona > Swakshetra > Friend's sign > Neutral's sign > Enemy's sign > Debilitation

Natural Friendship (Naisargika Maitri β€” BPHS Ch. 3)

Planet Friends Neutral Enemies
Sun Moon, Mars, Jupiter Mercury Venus, Saturn
Moon Sun, Mercury Mars, Jupiter, Venus, Saturn β€”
Mars Sun, Moon, Jupiter Venus, Saturn Mercury
Mercury Sun, Venus Mars, Jupiter, Saturn Moon
Jupiter Sun, Moon, Mars Saturn Mercury, Venus
Venus Mercury, Saturn Mars, Jupiter, Moon Sun
Saturn Mercury, Venus Jupiter Sun, Moon, Mars

Temporary Friendship Formula

distance = (sign_B - sign_A) % 12

  • Distances {1,2,3,9,10,11}: temporary friend
  • Distances {0,4,5,6,7,8}: temporary enemy
  • Distance 0 (self): excluded

Panchadha Maitri (Compound Relationship)

Natural + Temporary Compound
Friend + Friend Adhi Mitra (Great Friend)
Friend + Enemy Sama (Neutral)
Neutral + Friend Mitra (Friend)
Neutral + Enemy Shatru (Enemy)
Enemy + Friend Sama (Neutral)
Enemy + Enemy Adhi Shatru (Great Enemy)

Proposed Public Surface

EXALTATION_SIGN: dict[str, int]
EXALTATION_DEGREE: dict[str, float]
DEBILITATION_SIGN: dict[str, int]
MULATRIKONA_SIGN: dict[str, int]
MULATRIKONA_START: dict[str, float]
MULATRIKONA_END: dict[str, float]
OWN_SIGNS: dict[str, list[int]]
NATURAL_FRIENDS: dict[str, set[str]]
NATURAL_NEUTRALS: dict[str, set[str]]
NATURAL_ENEMIES: dict[str, set[str]]

class VedicDignityRank:
    EXALTATION   = "exaltation"
    MULATRIKONA  = "mulatrikona"
    OWN_SIGN     = "own_sign"
    FRIEND_SIGN  = "friend_sign"
    NEUTRAL_SIGN = "neutral_sign"
    ENEMY_SIGN   = "enemy_sign"
    DEBILITATION = "debilitation"

class CompoundRelationship:
    GREAT_FRIEND = "adhi_mitra"
    FRIEND       = "mitra"
    NEUTRAL      = "sama"
    ENEMY        = "shatru"
    GREAT_ENEMY  = "adhi_shatru"

@dataclass(frozen=True, slots=True)
class VedicDignityResult:
    planet: str
    sidereal_longitude: float
    sign_index: int
    sign: str
    dignity_rank: str
    is_exalted: bool
    is_debilitated: bool
    is_mulatrikona: bool
    is_own_sign: bool
    exaltation_score: float  # 0.0 at debilitation, 1.0 at deepest exaltation

@dataclass(frozen=True, slots=True)
class PlanetaryRelationship:
    from_planet: str
    to_planet: str
    natural: str    # "friend" / "neutral" / "enemy"
    temporary: str  # "friend" / "enemy"
    compound: str   # CompoundRelationship constant

def vedic_dignity(
    planet: str,
    sidereal_longitude: float,
) -> VedicDignityResult: ...

def planetary_relationships(
    sidereal_longitudes: dict[str, float],
) -> list[PlanetaryRelationship]: ...

Tricky Edge Cases

  • Mercury at Virgo 15Β° is at deepest exaltation AND at the start of its Mulatrikona range. Check exaltation before Mulatrikona in the cascade.
  • Moon's Mulatrikona: Parashara gives 3°–30Β°; some commentators give 4°–30Β°. Use 3Β° (primary source), document variant.
  • Scope: 7 classical planets only. Rahu and Ketu are not subjects of this system.

Estimated Complexity

Moderate.

System 3 β€” Jaimini Karakas

Primary Authority

Jaimini, Jaimini Sutras, Adhyaya 1, Pada 1, Sutras 1–14.

Validation Reference

Jhora (7/8-karaka mode); Sanjay Rath, Jaimini Maharishi's Upadesa Sutras (2002).

File

moira/jaimini.py

Core Algorithm

# 7-karaka scheme
planets_7 = ["Sun", "Moon", "Mars", "Mercury", "Jupiter", "Venus", "Saturn"]
degrees = {p: sidereal_lon[p] % 30.0 for p in planets_7}
sorted_planets = sorted(planets_7, key=lambda p: degrees[p], reverse=True)
# sorted_planets[0] = Atmakaraka, [1] = Amatyakaraka, ..., [6] = Darakaraka

Rahu (8-karaka scheme only): degree_in_sign = 30 - (rahu_sidereal_lon % 30) β€” inverted because Rahu moves retrograde.

Karaka Sequences

Rank 7-karaka 8-karaka
1 Atmakaraka (AK) Atmakaraka (AK)
2 Amatyakaraka (AmK) Amatyakaraka (AmK)
3 Bhratrikaraka (BK) Bhratrikaraka (BK)
4 Matrikaraka (MaK) Matrikaraka (MaK)
5 Pitrikaraka (PiK) Pitrikaraka (PiK)
6 Gnatikaraka (GK) Putrakaraka (PuK)
7 Darakaraka (DK) Gnatikaraka (GK)
8 β€” Darakaraka (DK)

Proposed Public Surface

KARAKA_NAMES_7: list[str]
KARAKA_NAMES_8: list[str]

@dataclass(frozen=True, slots=True)
class KarakaAssignment:
    karaka_name: str
    karaka_rank: int            # 1-based
    planet: str
    degree_in_sign: float       # effective degree used for sorting
    sidereal_longitude: float
    is_rahu_inverted: bool

@dataclass(frozen=True, slots=True)
class JaiminiKarakaResult:
    assignments: list[KarakaAssignment]
    scheme: int                              # 7 or 8
    atmakaraka: str                          # convenience accessor
    tie_warnings: list[tuple[str, str]]      # planet pairs with equal degrees

def jaimini_karakas(
    sidereal_longitudes: dict[str, float],
    scheme: int = 7,
) -> JaiminiKarakaResult: ...

def atmakaraka(
    sidereal_longitudes: dict[str, float],
    scheme: int = 7,
) -> str: ...

Tricky Edge Cases

  • Ketu is always excluded, even in the 8-karaka scheme. Only Rahu is the 8th candidate.
  • Ties: astronomically rare, but expose a tie_warning and apply a deterministic tiebreaker (document as indeterminate).
  • Atmakaraka at 29Β°59': valid edge case β€” no special handling needed, % 30 arithmetic handles it correctly.

Estimated Complexity

Simple. Core is a single sort with one special case (Rahu inversion).

System 4 β€” Panchanga

Primary Authority

Parashara, BPHS (Muhurta chapters). Varahamihira, Brihat Samhita Ch. 98–104.

Validation Reference

Jhora, Kala software.

File

moira/panchanga.py

Five Elements

Element Formula Span
Tithi int((moon_sid - sun_sid) % 360 / 12) + 1 12Β° each, 30 total
Vara int(jd + 1.5) % 7 β†’ Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn 1 day
Nakshatra delegate to sidereal.nakshatra_of(moon_tropical_lon, jd) 13.33Β° each
Yoga int((sun_sid + moon_sid) % 360 / (360/27)) + 1 13.33Β° each, 27 total
Karana half-Tithi (int(diff / 6)); 60 per month 6Β° each

Karana mapping: position 0 = Kimstughna (fixed); positions 1–56 cycle 7 movable Karanas; positions 57–59 = Shakuni, Chatushpada, Naga (fixed).

Each element should return degrees_elapsed and degrees_remaining to enable muhurta "time until next X" calculations.

Proposed Public Surface

TITHI_NAMES: list[str]     # 30 names: Pratipada … Amavasya
YOGA_NAMES: list[str]      # 27 names: Vishkumbha … Vaidhriti
KARANA_NAMES: list[str]    # 11 names
VARA_LORDS: list[str]      # 7 lords, Sunday-origin

@dataclass(frozen=True, slots=True)
class PanchangaElement:
    name: str
    index: int              # 0-based
    number: int             # 1-based
    degrees_elapsed: float
    degrees_remaining: float

@dataclass(frozen=True, slots=True)
class PanchangaResult:
    jd: float
    tithi: PanchangaElement
    vara: PanchangaElement
    vara_lord: str
    nakshatra: NakshatraPosition    # from sidereal.nakshatra_of
    yoga: PanchangaElement
    karana: PanchangaElement
    ayanamsa_system: str

def panchanga_at(
    sun_tropical_lon: float,
    moon_tropical_lon: float,
    jd: float,
    ayanamsa_system: str = Ayanamsa.LAHIRI,
) -> PanchangaResult: ...

Tricky Edge Cases

  • Vara boundary: The Vedic day begins at sunrise, not midnight. The base implementation operates on the astronomical JD and documents this limitation; sunrise-corrected Vara is a future policy parameter.
  • Yoga skipping: True fast Moon can skip a 13.33Β° Yoga window in a day. Use true positions (doctrine-consistent), note the skip possibility in the docstring.
  • Karana table boundary: The fixed Karanas at Amavasya/Pratipada are asymmetrically placed. Verify against Jhora at month boundaries.

Estimated Complexity

Moderate. Arithmetic is simple; Karana fixed/movable boundary requires careful table construction and validation.

System 5 β€” Alternative Dasha Systems

Primary Authority

  • Ashtottari: BPHS (Ashtottari Dasha chapter); Raman, A Manual of Hindu Astrology pp. 201–210.
  • Yogini: K.N. Rao, Yogini Dasha (1993); brief BPHS reference.
  • Kalachakra: BPHS (Kalachakra Dasha chapter); Sanjay Rath commentary.

Validation Reference

Jhora, Kala software. Kalachakra: Jhora is the primary cross-check.

File

moira/dasha_systems.py

Ashtottari (108-year cycle)

Sun:6, Moon:15, Mars:8, Mercury:17, Saturn:10, Jupiter:19, Rahu:12, Venus:21

Starting lord is from Moon's nakshatra β€” different mapping table from Vimshottari. Eligibility condition (Parashara): "Rahu not in 1st/5th/9th from Lagna" β€” expose bypass_eligibility: bool flag.

Yogini (36-year cycle)

Mangala (Moon):1, Pingala (Sun):2, Dhanya (Jupiter):3, Bhramari (Mars):4,
Bhadrika (Mercury):5, Ulka (Saturn):6, Siddha (Venus):7, Sankata (Rahu):8

Starting Yogini: nakshatra_index % 8. No eligibility condition. Sub-periods proportional (identical arithmetic to Vimshottari).

Kalachakra

Navamsha-based, Savya/Apasavya traversal direction, variable cycle length. Defer to Phase 2 within this module.

Proposed Public Surface

@dataclass(frozen=True, slots=True)
class AlternateDashaPeriod:
    system: str         # "ashtottari" | "yogini" | "kalachakra"
    level: int
    lord: str
    start_jd: float
    end_jd: float
    sub: list["AlternateDashaPeriod"]

@dataclass(frozen=True, slots=True)
class AshtottariPolicy:
    year_basis: str = "julian_365.25"
    ayanamsa_system: str = Ayanamsa.LAHIRI
    bypass_eligibility: bool = False
    lagna_sign_index: int | None = None   # required if bypass_eligibility=False

@dataclass(frozen=True, slots=True)
class YoginiPolicy:
    year_basis: str = "julian_365.25"
    ayanamsa_system: str = Ayanamsa.LAHIRI

def ashtottari(
    moon_tropical_lon: float,
    natal_jd: float,
    levels: int = 2,
    policy: AshtottariPolicy | None = None,
) -> list[AlternateDashaPeriod]: ...

def yogini_dasha(
    moon_tropical_lon: float,
    natal_jd: float,
    levels: int = 2,
    policy: YoginiPolicy | None = None,
) -> list[AlternateDashaPeriod]: ...

Estimated Complexity

  • Ashtottari: Simple (structurally identical to Vimshottari, different tables + one eligibility condition)
  • Yogini: Simple (8 lords, proportional sub-periods, no eligibility)
  • Kalachakra: Complex (Savya/Apasavya traversal, Navamsha-sign mapping, variable cycle) β€” Phase 2

System 6 β€” Ashtakavarga

Primary Authority

Parashara, BPHS Ashtakavarga Adhyaya. Vaidyanatha Dikshita, Jataka Parijata (14th c.).

Engineering Reference

B.V. Raman, Ashtakavarga System of Prediction (1981) β€” the canonical English-language reference with verified tables. Commit to Raman as the authoritative table source; document it explicitly.

Validation Reference

Jhora (Bhinnashtakavarga display), Kala software.

File

moira/ashtakavarga.py

Algorithm

for planet_P in seven_planets:
    bhinna_AV[planet_P] = [0] * 12
    for sign_i in range(12):
        for ref in [*seven_planets, "Lagna"]:
            distance = (sign_i - sign_index[ref]) % 12 + 1   # 1–12
            if distance in REKHA_TABLES[planet_P][ref]:
                bhinna_AV[planet_P][sign_i] += 1

sarva[sign_i] = sum(bhinna_AV[P][sign_i] for P in seven_planets)

The REKHA_TABLES are 7 Γ— 8 fixed lookup tables β€” 672 individual rekha/no-rekha values that must be encoded verbatim from Raman's reference and verified sign-by-sign against Jhora.

Phase 1: Unreduced Bhinnashtakavarga + Sarvashtakavarga.
Phase 2: Trikona Shodhana and Ekadhipatya Shodhana (reductions).

Proposed Public Surface

REKHA_TABLES: dict[str, dict[str, frozenset[int]]]  # 7 planets Γ— 8 references

@dataclass(frozen=True, slots=True)
class BhinnashtakavargaResult:
    planet: str
    rekhas: tuple[int, ...]     # 12 counts, 0=Aries…11=Pisces
    total_rekhas: int           # sum (always 0–56)

@dataclass(frozen=True, slots=True)
class AshtakavargaResult:
    jd: float
    ayanamsa_system: str
    bhinnashtakavarga: dict[str, BhinnashtakavargaResult]
    sarvashtakavarga: tuple[int, ...]    # 12 aggregate counts

def bhinnashtakavarga(
    planet: str,
    sign_indices: dict[str, int],       # planet/lagna β†’ sign index (0–11)
) -> BhinnashtakavargaResult: ...

def ashtakavarga(
    sidereal_longitudes: dict[str, float],   # includes "Lagna" key
) -> AshtakavargaResult: ...

def transit_strength(
    planet: str,
    transit_sign_index: int,
    bhinna: BhinnashtakavargaResult,
) -> int: ...    # 0–8

Tricky Edge Cases

  • Table variants: different BPHS editions have minor discrepancies. Commit to Raman (1981) and document.
  • Lagna participates as a sign index only β€” no longitude precision needed.
  • Rahu/Ketu: excluded from core system. Scope to 7 planets + Lagna. Document as future extension.

Estimated Complexity

Moderate. Algorithm is simple; table transcription is the primary failure mode.

System 7 β€” Shadbala

Primary Authority

Parashara, BPHS Shadbala Adhyaya.

Engineering Reference

B.V. Raman, Graha and Bhava Balas (1959) β€” fully worked example chart verifiable to 2 decimal places in Rupas. Use this as the primary test fixture.

Validation Reference

Jhora full Shadbala display.

File

moira/shadbala.py

Unit

Shashtiamsas (Sha). 60 Sha = 1 Rupa.

Six Components

1. Sthana Bala (Positional Strength) β€” 5 sub-components

(a) Uchcha Bala

dist = abs(sidereal_lon - exaltation_lon)
if dist > 180: dist = 360 - dist
uchcha_bala = (180 - dist) / 3.0    # Sha, max 60

(b) Saptavargaja Bala β€” dignity in each of D1, D2, D3, D7, D9, D12, D30

Dignity in varga Shashtiamsas
Exaltation 20
Own sign 15
Adhi Mitra (great friend) 10
Mitra (friend) 7.5
Sama (neutral) 5
Shatru (enemy) 2.5
Adhi Shatru (great enemy) 1.25
Debilitation 0

Sum across 7 vargas. Max = 140 Sha.

(c) Ojayugmarasyamsa Bala β€” odd/even sign strength
Sun, Mars, Jupiter, Saturn: 15 Sha in odd D1/D9 signs. Moon, Venus: 15 Sha in even signs.

(d) Kendradi Bala β€” angular house
Kendra (1,4,7,10): 60 Sha. Panapara (2,5,8,11): 30 Sha. Apoklima (3,6,9,12): 15 Sha.

(e) Drekkana Bala
Male planets (Sun, Mars, Jupiter) in 1st drekkana: 15 Sha. Hermaphrodite (Mercury, Saturn) in 2nd: 15 Sha. Female (Moon, Venus) in 3rd: 15 Sha.

2. Dig Bala (Directional Strength)

Strong direction by planet:

Sun, Mars:         10th house cusp
Jupiter, Mercury:  1st house cusp (Ascendant)
Moon, Venus:       4th house cusp
Saturn:            7th house cusp

dist = abs(sidereal_lon - strong_cusp_lon)
if dist > 180: dist = 360 - dist
dig_bala = (180 - dist) / 3.0    # Sha, max 60

3. Kala Bala (Temporal Strength) β€” 6 sub-components

Sub-component Key
Nathonnatha Day planets (Sun, Jupiter, Venus) max at noon; night planets (Moon, Mars, Saturn) max at midnight; Mercury always strong.
Paksha Tithi 1–15: shukla = tithi. Tithi 16–30: shukla = 30 - tithi. Benefics: shukla * 4 Sha. Malefics: (15 - shukla) * 4 Sha.
Tribhaga Jupiter: 1st third of day; Sun: 2nd; Saturn: 3rd. Moon: 1st third of night; Venus: 2nd; Mars: 3rd. Mercury: always. Value: 60 Sha in strong period, 0 otherwise.
Abda/Masa/Vara/Hora Lord of current solar year, month, weekday, hour each receive 15 Sha.
Ayana ayana_bala = 24 * sin(Sun_declination). sin(dec) = sin(obliquity) Γ— sin(sun_lon).
Yuddha Planets within 1Β° in same sign: victor (smaller longitude) gains loser's Yuddha Bala.

4. Chesta Bala (Motional Strength)

Speed-based score vs mean speed. Retrograde = maximum (60 Sha). Sun and Moon: distance from apogee/perigee.

5. Naisargika Bala (Natural Fixed Strength β€” never changes)

Planet Sha
Sun 60.00
Moon 51.43
Venus 42.85
Jupiter 34.28
Mercury 25.70
Mars 17.14
Saturn 8.57

6. Drig Bala (Aspectual Strength)

Sum weighted benefic aspects received; subtract weighted malefic aspects. Vedic aspect weights: full (7th sign) = 1.0; three-quarter (Mars: 4th/8th; Jupiter: 5th/9th; Saturn: 3rd/10th) = 0.75; half (5th/9th regular) = 0.5; quarter (3rd/10th regular) = 0.25.

Required Minimum Rupas

Planet Min Rupas
Sun 6.5
Moon 6.0
Mars 5.0
Mercury 7.0
Jupiter 6.5
Venus 5.5
Saturn 5.0

Proposed Public Surface

@dataclass(frozen=True, slots=True)
class SthanaBala:
    uchcha: float; saptavargaja: float; ojayugma: float
    kendradi: float; drekkana: float; total: float

@dataclass(frozen=True, slots=True)
class KalaBala:
    nathonnatha: float; paksha: float; tribhaga: float
    abda_masa_vara_hora: float; ayana: float; yuddha: float; total: float

@dataclass(frozen=True, slots=True)
class PlanetShadbala:
    planet: str
    sthana_bala: SthanaBala
    dig_bala: float
    kala_bala: KalaBala
    chesta_bala: float
    naisargika_bala: float
    drig_bala: float
    total_shashtiamsas: float
    total_rupas: float
    required_rupas: float
    is_sufficient: bool

@dataclass(frozen=True, slots=True)
class ShadbalaResult:
    jd: float
    ayanamsa_system: str
    planets: dict[str, PlanetShadbala]   # 7 planets

def shadbala(
    sidereal_longitudes: dict[str, float],
    planet_speeds: dict[str, float],
    houses: "HouseCusps",
    jd: float,
    latitude: float,
    longitude: float,
    ayanamsa_system: str = Ayanamsa.LAHIRI,
) -> ShadbalaResult: ...

# Individual sub-component functions for testing:
def sthana_bala(planet: str, sidereal_lon: float, ...) -> SthanaBala: ...
def dig_bala(planet: str, sidereal_lon: float, houses: "HouseCusps") -> float: ...
def kala_bala(planet: str, jd: float, latitude: float, longitude: float, ...) -> KalaBala: ...
def chesta_bala(planet: str, speed: float, mean_speed: float) -> float: ...
def drig_bala(planet: str, sidereal_longitudes: dict[str, float]) -> float: ...

Tricky Edge Cases

  • Saptavargaja requires completed varga.py (all 7 vargas, especially D2 Hora with Parashari rule). This is the hard dependency on System 1.
  • Kala Bala requires sunrise/sunset β€” lat/lon input is mandatory. This makes Shadbala the only system with an indirect dependency on moira.rise_set.
  • Ayana Bala declination: sin(dec) = sin(obliquity) Γ— sin(sun_lon). Use moira.obliquity.mean_obliquity(jd).
  • Chesta Bala for luminaries: Sun uses distance from aphelion; Moon uses distance from perigee. Requires mean anomaly from moira.planets speed data or moira.nodes.
  • Yuddha threshold: Planetary war is restricted to same-sign conjunctions within 1Β°.
  • Bhava Bala (house strength) is a related but separate system β€” keep out of scope.

Estimated Complexity

Complex. Highest sub-component count and most input dependencies of all 7 systems. Implement each sub-component as an isolated function with its own test fixture from Raman's Graha and Bhava Balas reference chart.

Consolidated Dependency Map

moira/sidereal.py      β€” complete; provides tropical_to_sidereal, nakshatra_of, Ayanamsa
moira/varga.py         β€” extend with 11 missing wrappers (D2/D4/D6/D8/D16/D20/D24/D27/D40/D45/D60)
moira/cycles.py        β€” complete; weekday ruler available
moira/rise_set.py      β€” complete; sunrise/sunset (required by Shadbala Kala Bala)

moira/panchanga.py        ← sidereal.py, cycles.py
moira/vedic_dignities.py  ← sidereal.py, constants.py
moira/jaimini.py          ← sidereal.py
moira/dasha_systems.py    ← sidereal.py (patterns from dasha.py)
moira/ashtakavarga.py     ← vedic_dignities.py (needed for Shodhana; not for base)
moira/shadbala.py         ← varga.py (all 7), vedic_dignities.py, panchanga.py,
                             ashtakavarga.py (optional Drig Bala variant),
                             rise_set.py, nodes.py (Moon apogee for Chesta Bala)

Authority Source Quick Reference

System Primary Canon Engineering Reference
Shodashvarga BPHS Ch. 6–22 Jhora, Parashara Light 9.x
Vedic Dignities BPHS Ch. 3, 26, 28; Saravali Ch. 5–6 Raman, A Manual of Hindu Astrology
Jaimini Karakas Jaimini Sutras, Adhyaya 1, Pada 1 Sanjay Rath commentary; Jhora
Panchanga BPHS Muhurta chapters; Brihat Samhita Ch. 98–104 Jhora, Kala
Alt. Dashas BPHS (Ashtottari/Kalachakra chapters); Rao, Yogini Dasha Jhora, Kala
Ashtakavarga BPHS Ashtakavarga Adhyaya; Jataka Parijata Raman, Ashtakavarga System of Prediction (1981)
Shadbala BPHS Shadbala Adhyaya Raman, Graha and Bhava Balas (1959)