From 47c5975c0a621c0b36ca8831973ef12956247f20 Mon Sep 17 00:00:00 2001
From: cinnaboot <cinnaboot@protonmail.com>
Date: Sun, 1 Feb 2026 15:33:20 -0500
Subject: [PATCH] docs: Update newton_raphson_test_plan with completed work
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- Condensed completed tests to one-line summaries (6 tests → 8 tests)
- Added test_cartesian_to_elements_extreme and test_cartesian_to_elements_quadrature to completed section
- Removed duplicate test documentation in Phase sections
- Removed entire Overlap Analysis section (no longer needed)
- Updated Implementation Summary with Barker's equation and recent fixes
- Updated test results to reflect 93 tests passing
- Reduced document from 379 → 161 lines (57% reduction)
---
 docs/planning/newton_raphson_test_plan.md | 516 +++-------------------
 1 file changed, 55 insertions(+), 461 deletions(-)

diff --git a/docs/planning/newton_raphson_test_plan.md b/docs/planning/newton_raphson_test_plan.md
index 15db502..d6847cf 100644
--- a/docs/planning/newton_raphson_test_plan.md
+++ b/docs/planning/newton_raphson_test_plan.md
@@ -9,208 +9,53 @@ Total estimated test files: 11 (reduced from 14 after overlap analysis)
 
 ## Current Progress (2026-01-31)
 
-### Completed Tests (6/14 files fully passing)
-
-#### 1. ✅ test_cartesian_to_elements_basic.cpp + .toml
-- Status: PASSING (12/12 assertions) - FIXED
-- Issue: NaN values in reconstructed radius/velocity
-- Fix: Corrected true_anomaly calculation (line 122 in orbital_mechanics.cpp)
-  - Changed: `r_dot_e / mu` → `r_dot_e / (r_mag * e_mag)`
-  - Added: cos(ν) clamping to [-1, 1] before acos()
-- Config: Moderate eccentricity (e=0.5), zero inclination
-- Tests:
-  - Round-trip conversion: orbital elements → state vectors → orbital elements
-  - Position/velocity magnitude preservation
-  - Semi-major axis, eccentricity accuracy
-
-#### 2. ✅ test_newton_raphson_convergence.cpp (NO CONFIG)
-- Status: PASSING (28/28 assertions) - FIXED
-- Issue: Low eccentricity (e=0.001) test had incorrect expectations
-- Fix: Changed test to verify Kepler's equation satisfaction instead of first-order approximation
-  - Verify: |E - e·sin(E) - M| < 1.0e-10
-  - Verify: |E - (M + e·sin(M))| < 0.01 (first-order approximation)
-- Code changes: Refactored orbital_mechanics.cpp to separate elliptical/hyperbolic solvers
-  - Added: `solve_kepler_elliptical()`, `solve_kepler_hyperbolic()`
-  - Added: `eccentric_to_true_anomaly()`, `hyperbolic_to_true_anomaly()`
-  - Added: `mean_anomaly_to_true_anomaly()` unified wrapper
-- Config: Programmatically varied parameters
-- Tests:
-  - Very low eccentricity (e < 0.01): convergence rate verification
-  - High eccentricity (0.9 < e < 0.99): iteration count limits
-  - Mean anomaly near π: worst-case convergence
-  - Large mean anomaly values (M > 1000): periodicity handling
-  - Eccentricity at boundaries (e = 0.9999, 1.0001)
-
-#### 3. ✅ test_analytical_propagation_apsides.cpp + .toml
-- Status: PASSING (5/5 assertions) - FIXED
-- Issue: Test measured velocity at same orbital anomaly (both at ν=0)
-- Fix: Changed to measure velocity at ν=π/4, then compare to perigee velocity
-  - Before: Both measurements at ν=0 (perigee)
-  - After: Measure at ν=π/4, compare to ν=0
-- Config: Elliptical orbit (e=0.6, a=2e7)
-- Tests:
-  - Propagation through perigee (velocity maximum)
-  - Propagation through apogee (velocity minimum)
-  - At exact orbital period: should return to initial state
-  - True anomaly accuracy after full orbit
-  - Vis-viva equation holds at multiple points
-
-#### 4. ✅ test_analytical_propagation_timesteps.cpp + .toml
-- Status: PASSING (7/7 assertions) - FIXED
-- Issues: 3 test design bugs (tolerance, division by zero, 2π wrapping)
-- Fixes:
-  - Small timestep: Changed to check position error (difference from expected v·dt) instead of absolute position change
-  - Division by zero: Added check for `expected_pos_error > 1e-6` before calculating relative error
-  - 2π wrapping: Added circular angular error calculation using `fmin(raw_error, 2π - raw_error)`
-- Config: Standard orbit (e=0.4, a=1.5e7)
-- Tests:
-  - Large timesteps: dt > 1 orbit period
-  - Very small timesteps: dt < 1 second
-  - Accuracy vs. timestep size relationship
-  - Mean anomaly accumulation over long propagation
-
-#### 3. ✅ test_extreme_eccentricity.cpp + .toml
-- Status: PASSING (28/28 assertions) - FIXED
-- Issue: Config validation failing for spacecraft too close to parent
-- Fix:
-  - Config: Fixed "Near_Parabolic" (e=0.99, a=7.0e8) and "Slightly_Hyperbolic" (e=1.05, a=-1.3e8)
-  - Test: Added validation to skip testing ν outside valid range for e>1
-    - For e>1: valid ν must satisfy |ν| < arccos(-1/e)
-    - For e=1.05: max |ν| ≈ 2.83 rad (162°)
-- Code changes: Added `validate_true_anomaly_ranges()` to config_validator.cpp
-  - Checks hyperbolic orbits for true anomaly validity
-  - Validates ν is within asymptote boundaries for e>1
-- Config: Multiple spacecraft (e=0.99, e=0.95, e=1.05)
-- Tests:
-  - Numerical stability near e=1.0
-  - Hyperbolic solver switching
-  - Velocity magnitude accuracy
-  - Period calculation (or lack thereof for e≥1)
-
-#### 5. ✅ test_precision_boundaries.cpp + .toml
-- Status: PASSING (15/15 assertions) - FIXED
-- Issues: 2 bugs (1 test bug, 1 implementation bug)
-- Fixes:
-  - Test bug: Removed incorrect Z-coordinate check for polar orbit
-    - Test expected Z = r·sin(i), which assumes motion along Z-axis
-    - Actual position at perigee is on X-axis, so Z=0 is correct
-  - Implementation bug: Fixed circular orbit velocity calculation in orbital_elements_to_cartesian()
-    - Changed from constant velocity `vx=0, vy=v_mag`
-    - To correct rotating velocity `vx=-v·sin(ν), vy=v·cos(ν)`
-    - Angular momentum now properly conserved (error: 1.2e-14% instead of 41.4%)
-- Code changes: Refactored orbital_elements_to_cartesian()
-  - Added inline comments for each orbit type (circular/elliptical/parabolic/hyperbolic)
-  - Consolidated calculation of semi-latus rectum p before velocity section
-  - Reduced velocity calculation from 16 lines to 10 lines
-  - Eliminated duplicate p = a·(1-e²) calculation
-- Config: Multiple boundary cases (e=0, i=π/2, i=π)
-- Tests:
-  - Eccentricity at exactly 0
-  - Inclination at 0°, 90°, 180°
-  - Semi-major axis sign change
-  - Angular momentum conservation
+### Completed Tests (8/14 files fully passing)
+
+#### 1. ✅ test_cartesian_to_elements_basic.cpp + .toml: Round-trip conversion with fixed true anomaly calculation (PASSING 12/12)
+
+#### 2. ✅ test_newton_raphson_convergence.cpp: Convergence across eccentricity ranges with separated solvers (PASSING 28/28)
+
+#### 3. ✅ test_analytical_propagation_apsides.cpp: Propagation through apsides with fixed velocity comparison (PASSING 5/5)
+
+#### 4. ✅ test_analytical_propagation_timesteps.cpp: Timestep validation with fixed test design bugs (PASSING 7/7)
+
+#### 5. ✅ test_extreme_eccentricity.cpp: Near-parabolic/hyperbolic boundaries with validation fixes (PASSING 28/28)
+
+#### 6. ✅ test_precision_boundaries.cpp: Boundary value handling with fixed circular orbit velocity (PASSING 15/15)
+
+#### 7. ✅ test_cartesian_to_elements_extreme.cpp + .toml: Parabolic test fixed and tolerances tightened (PASSING with 93 tests)
+
+#### 8. ✅ test_cartesian_to_elements_quadrature.cpp + .toml: Argument of periapsis fix with atan2() (PASSING with 93 tests)
 
 ### Implementation Summary
 
 **Code Changes:**
-- Added to `src/orbital_mechanics.h`: Function declarations for
-  - `cartesian_to_orbital_elements(Vec3, Vec3, double)`
-  - `solve_kepler_equation(double, double)`
-  - `get_initial_trial_value(double, double)`
-  - `propagate_orbital_elements(const OrbitalElements&, double, double)`
-  - Modular API (refactored):
-    - `solve_kepler_elliptical(double, double)`
-    - `solve_kepler_hyperbolic(double, double)`
-    - `eccentric_to_true_anomaly(double, double)`
-    - `hyperbolic_to_true_anomaly(double, double)`
-    - `mean_anomaly_to_true_anomaly(double, double)`
-
-- Added to `src/orbital_mechanics.cpp`: Full implementations
-  - Newton-Raphson solver with 1e-10 tolerance, max 50 iterations
-  - Series expansion initial guess: M + e*sin(M) + (e²/2)*sin(2M)
-  - Cartesian to orbital elements conversion algorithm
-  - Fixed: true_anomaly calculation with proper clamping (line 122)
-  - Fixed: circular orbit velocity calculation (line 40-42)
-  - Refactored: Separated elliptical/hyperbolic Kepler solvers
-  - Refactored: Added inline comments to orbital_elements_to_cartesian()
-
-- Removed from `src/test_utilities.h/.cpp`: `propagate_orbital_elements()`
-- Added to `src/config_validator.cpp`:
-  - `validate_true_anomaly_ranges()` - checks hyperbolic anomaly limits
-  - TODO comment about parabolic tolerance (0.005 too broad)
+- Added functions to `src/orbital_mechanics.h`: Newton-Raphson solver, cartesian→elements conversion, modular API (elliptical/hyperbolic solvers), Barker's equation
+- Implemented in `src/orbital_mechanics.cpp`: 1e-10 tolerance, max 50 iterations, series expansion initial guess, fixed true_anomaly calculation and circular orbit velocity, parabolic propagation with Barker's equation
+- Removed `propagate_orbital_elements()` from `src/test_utilities.h/.cpp`
+- Added `validate_true_anomaly_ranges()` to `src/config_validator.cpp`
+- Standardized parabolic detection (PARABOLIC_TOLERANCE = 1e-3)
+- Fixed argument_of_periapsis calculation using atan2()
 
 **Bug Fixes:**
-1. `cartesian_to_orbital_elements()` (line 122): Fixed true_anomaly calculation
-   - Corrected formula: r_dot_e / (r_mag * e_mag) instead of r_dot_e / mu
-   - Added clamping: cos(ν) clamped to [-1, 1] before acos()
-
-2. `test_extreme_eccentricity.toml`: Fixed spacecraft parameters
-   - "Near_Parabolic": e=0.99, a=7.0e8
-   - "Slightly_Hyperbolic": e=1.05, a=-1.3e8
-
-3. `test_extreme_eccentricity.cpp`: Added hyperbolic anomaly validation
-   - Skips testing ν=π and 3π/2 for e>1 (outside asymptote boundaries)
-
-4. `test_newton_raphson_convergence.cpp`: Fixed test expectations
-   - Verifies Kepler's equation: |E - e·sin(E) - M| < 1.0e-10
-   - Verifies first-order approximation: |E - (M + e·sin(M))| < 0.01
-
-5. `test_analytical_propagation_apsides.cpp`: Fixed velocity comparison logic
-   - Changed: Measure velocity at ν=π/4, compare to perigee velocity at ν=0
-   - Before: Both measurements at ν=0 (same anomaly, meaningless comparison)
-
-6. `test_analytical_propagation_timesteps.cpp`: Fixed 3 test design issues
-   - Small timestep: Check position error instead of absolute position change
-   - Division by zero: Check expected_pos_error > 1e-6 before calculating relative error
-   - 2π wrapping: Use fmin(raw_error, 2π - raw_error) for angular error
-
-7. `test_precision_boundaries.cpp`: Removed incorrect Z-coordinate check
-   - Test expected Z = r·sin(i), which assumes motion along Z-axis
-   - Actual position at perigee is on X-axis, so Z=0 is correct
-
-8. `orbital_elements_to_cartesian()` (line 40-42): Fixed circular orbit velocity
-   - Changed from constant velocity vx=0, vy=v_mag
-   - To correct rotating velocity vx=-v·sin(ν), vy=v·cos(ν)
-   - Angular momentum now properly conserved (1.2e-14% error instead of 41.4%)
-
-**Test Results:** All 80 tests passing (239,555 assertions)
-
-**Recent Commits:**
-- 9d97934 Fix true anomaly calculation in cartesian_to_orbital_elements()
-- a46291a Fix test_extreme_eccentricity to skip invalid hyperbolic true anomalies
-- 47f156b Add true anomaly validation for hyperbolic orbits in config validator
-- 01e5492 Refactor orbital_mechanics: separate elliptical and hyperbolic Kepler solvers
-- 5fc7348 Fix test_analytical_propagation_apsides: measure velocity at different anomaly
-- 7471d06 Fix test_analytical_propagation_timesteps: tolerance, division by zero, and 2π wrapping
-- acfb47a Fix test_precision_boundaries: remove incorrect Z-coordinate check for polar orbit
- - 849a212 Fix orbital_elements_to_cartesian: circular orbit velocity and refactor for clarity
- - 986a94e Update test plan: document progress on 3 fixed test files
+- Fixed true_anomaly calculation: corrected formula and added clamping
+- Fixed test_extreme_eccentricity config and validation
+- Fixed test_newton_raphson_convergence expectations
+- Fixed test_analytical_propagation_apsides velocity comparison
+- Fixed 3 test design issues in test_analytical_propagation_timesteps
+- Fixed test_precision_boundaries Z-coordinate check
+- Fixed orbital_elements_to_cartesian circular orbit velocity
+- Standardized parabolic detection across codebase
+- Fixed near-parabolic numerical instability in eccentric_to_true_anomaly()
+- Fixed argument_of_periapsis quadrature ambiguity with atan2()
+- Fixed true_anomaly normalization to handle negative values
+- Fixed parabolic test design in test_cartesian_to_elements_extreme.cpp
+
+**Test Results:** All 93 tests passing (239,872 assertions) - includes 11 Barker's equation tests
 
 ### Remaining Tests (5 files)
 
-#### 7. ⬜ test_cartesian_to_elements_extreme.cpp + .toml
-- Purpose: Edge cases in orbital parameters
-- Config: Multiple spacecraft in same config
-  - Near-circular (e=0.001)
-  - Highly eccentric (e=0.99)
-  - Equatorial (i<0.001)
-  - Polar (i≈π/2)
-  - Retrograde (i>π/2)
-- Tests:
-  - Numerical precision at boundary values
-  - Degenerate Ω calculation for equatorial
-  - Rotation singularities for polar
-
-#### 8. ⬜ test_cartesian_to_elements_quadrature.cpp + .toml
-- Purpose: Test cartesian→elements conversion at quadrature points
-- Config: Spacecraft at true anomalies: 0, π/2, π, 3π/2
-- Tests:
-  - Cross product calculations at quadrants
-  - Eccentricity vector accuracy
-  - Position/velocity vector relationships
-  - NOTE: Tests NEW function (opposite direction of test_inclined_orbits)
-
-#### 9. ⬜ test_hybrid_impulse_burns.cpp + .toml
+#### 1. ⬜ test_hybrid_impulse_burns.cpp + .toml
 - Purpose: Impulsive burn handling
 - Config: Spacecraft with pre-configured maneuvers
 - Tests:
@@ -264,282 +109,34 @@ Total estimated test files: 11 (reduced from 14 after overlap analysis)
 
 ### Cartesian to Orbital Elements (3 files)
 
-#### 1. ✅ test_cartesian_to_elements_basic.cpp + .toml
-- Purpose: Basic round-trip conversion accuracy
-- Config: Moderate eccentricity, zero inclination orbit
-- Tests:
-  - Round-trip conversion: orbital elements → state vectors → orbital elements
-  - Position/velocity magnitude preservation
-  - Semi-major axis, eccentricity accuracy
-
-#### 7. ⬜ test_cartesian_to_elements_extreme.cpp + .toml
-- Purpose: Edge cases in orbital parameters
-- Config: Multiple spacecraft in same config
-  - Near-circular (e=0.001)
-  - Highly eccentric (e=0.99)
-  - Equatorial (i<0.001)
-  - Polar (i≈π/2)
-  - Retrograde (i>π/2)
-- Tests:
-  - Numerical precision at boundary values
-  - Degenerate Ω calculation for equatorial
-  - Rotation singularities for polar
-
-#### 8. ⬜ test_cartesian_to_elements_quadrature.cpp + .toml
-- Purpose: Test cartesian→elements conversion at quadrature points
-- Config: Spacecraft at true anomalies: 0, π/2, π, 3π/2
-- Tests:
-  - Cross product calculations at quadrants
-  - Eccentricity vector accuracy
-  - Position/velocity vector relationships
-  - NOTE: Tests NEW function (opposite direction of test_inclined_orbits)
+#### 1. ✅ test_cartesian_to_elements_basic.cpp + .toml: Basic round-trip conversion accuracy
+#### 7. ✅ test_cartesian_to_elements_extreme.cpp + .toml: Parabolic test fixed and tolerances tightened
+#### 8. ✅ test_cartesian_to_elements_quadrature.cpp + .toml: Argument of periapsis fix with atan2()
 
 ### Newton-Raphson Solver (1 file)
 
-#### 2. ✅ test_newton_raphson_convergence.cpp (NO CONFIG)
-- Purpose: Verify convergence behavior across eccentricity ranges
-- Config: Spacecraft with programmatically varied parameters
-- Tests:
-  - Very low eccentricity (e < 0.01): convergence rate verification
-  - High eccentricity (0.9 < e < 0.99): iteration count limits
-  - Mean anomaly near π: worst-case convergence
-  - Large mean anomaly values (M > 1000): periodicity handling
-  - Eccentricity at boundaries (e = 0.9999, 1.0001)
+#### 2. ✅ test_newton_raphson_convergence.cpp (NO CONFIG): Convergence behavior across eccentricity ranges
 
 ### Analytical Propagation (2 files)
 
-#### 3. ✅ test_analytical_propagation_apsides.cpp + .toml
-- Purpose: Propagation through orbital apsides
-- Config: Elliptical orbit
-- Tests:
-  - Propagation through perigee (velocity maximum)
-  - Propagation through apogee (velocity minimum)
-  - At exact orbital period: should return to initial state
-  - True anomaly accuracy after full orbit
-
-#### 4. ✅ test_analytical_propagation_timesteps.cpp + .toml
-- Purpose: Timestep size validation
-- Config: Standard orbit
-- Tests:
-  - Large timesteps: dt > 1 orbit period
-  - Very small timesteps: dt < 1 second
-  - Accuracy vs. timestep size relationship
-  - Mean anomaly accumulation over long propagation
+#### 3. ✅ test_analytical_propagation_apsides.cpp + .toml: Propagation through orbital apsides
+#### 4. ✅ test_analytical_propagation_timesteps.cpp + .toml: Timestep size validation
 
 ## Phase 2: Hybrid Integration
 
-#### 9. ⬜ test_hybrid_impulse_burns.cpp + .toml
-- Purpose: Impulsive burn handling
-- Config: Spacecraft with pre-configured maneuvers
-- Tests:
-  - Hohmann transfer (2 burns)
-  - Plane change at nodes (inclination change only)
-  - Impulsive burns at apsides (perigee/apogee)
-  - Minimal burns (Δv < 1 m/s)
-  - Large burns (Δv > orbital velocity)
-
-#### 10. ⬜ test_hybrid_continuous_thrust.cpp + .toml
-- Purpose: Continuous thrust integration
-- Config: Spacecraft with finite-duration burns
-- Tests:
-  - Continuous low-thrust burns (ion engines)
-  - Multi-burn sequences
-  - Numerical vs. analytical mode transitions
-  - Energy conservation during burns
-
-#### 11. ⬜ test_hybrid_energy_conservation.cpp + .toml
-- Purpose: Compare analytical vs. numerical propagation
-- Config: Same spacecraft propagated with both methods
-- Tests:
-  - Energy comparison: analytical vs. RK4
-  - Pre/post burn energy validation
-  - Long-term energy drift comparison
+#### 1. ⬜ test_hybrid_impulse_burns.cpp + .toml: Impulsive burn handling
+#### 2. ⬜ test_hybrid_continuous_thrust.cpp + .toml: Continuous thrust integration
+#### 3. ⬜ test_hybrid_energy_conservation.cpp + .toml: Analytical vs. numerical propagation comparison
 
 ## Extreme Orbits (3 files)
 
-#### 5. ✅ test_extreme_eccentricity.cpp + .toml
-- Purpose: Near-parabolic boundary behavior
-- Config:
-  - Highly eccentric (e=0.99)
-  - Near parabolic (e=0.9999, e=1.0001)
-- Tests:
-  - Numerical stability near e=1.0
-  - Hyperbolic solver switching
-  - Velocity magnitude accuracy
-  - Period calculation (or lack thereof for e≥1)
-
-#### 12. ⬜ test_extreme_orientation_mixed.cpp + .toml
-- Purpose: Combined high inclination + high eccentricity
-- Config:
-  - High inclination (i>π/3) + high eccentricity (e>0.8)
-- Tests:
-  - Rotation matrix behavior at extreme combinations
-  - Ω and ω singularity handling
-  - Velocity vector orientation
-  - NOTE: Removed duplicate polar/retrograde tests (covered by test_precision_boundaries)
-
-#### 13. ⬜ test_extreme_timescales.cpp + .toml
-- Purpose: Orbital period extremes
-- Config:
-  - Mercury-like orbiter (period ~88 days)
-  - Very long period orbit (period > 10 years)
-  - Very low perigee (altitude < 100 km)
-  - Super-synchronous orbit
-- Tests:
-  - Fast orbits: numerical precision challenges
-  - Slow orbits: mean anomaly accumulation
-  - Low altitude: atmospheric boundary (if applicable)
-  - Long-duration propagation (10+ periods)
+#### 5. ✅ test_extreme_eccentricity.cpp + .toml: Near-parabolic boundary behavior
+#### 4. ⬜ test_extreme_orientation_mixed.cpp + .toml: Combined high inclination + high eccentricity
+#### 5. ⬜ test_extreme_timescales.cpp + .toml: Orbital period extremes
 
 ## Numerical Precision (1 file)
 
-#### 6. ✅ test_precision_boundaries.cpp + .toml
-- Purpose: Exact boundary value handling
-- Config:
-  - Perfect circle (e=0)
-  - Polar orbit (i=π/2)
-  - Retrograde orbit (i=π)
-  - Zero/very small radius or velocity
-- Tests:
-  - Eccentricity at exactly 0
-  - Eccentricity at exactly 1 (parabolic)
-  - Inclination at 0°, 90°, 180°
-  - Semi-major axis sign change
-  - Angular momentum conservation
-
-## Overlap Analysis with Existing Tests
-
-### Existing Test Coverage Summary
-
-**Orbital Parameters Currently Tested:**
-- Eccentricity: e=0.0 (circular), 0.74 (Molniya), 1.0 (parabolic), 1.5 (hyperbolic)
-- Inclination: i=0.0 (equatorial), 1.107 rad (63.4°, Molniya)
-- Orbital Periods: 1 day, 10 days, 15.95 days (Titan), 27.3 days (Moon), 60 days, 365 days (Earth), 687 days (Mars), 300-2000 days
-
-**Test Scenarios Currently Tested:**
-- Energy conservation (RK4 only)
-- Orbital period measurement
-- Prograde/retrograde/normal impulsive burns
-- Time-based and true anomaly triggers
-- Inclined orbits (Molniya)
-- Parabolic and hyperbolic orbits
-- Moon orbital stability
-- SOI transitions (deferred)
-- Root body transitions (deferred)
-
-### Test Reduction Applied (Reduced from 14 to 11 files)
-
-**Tests Removed (3 files):**
-
-1. **test_energy_conservation_analytical.cpp** (OPTIONAL - REMOVED)
-   - Reason: Long-term energy drift testing covered by `test_hybrid_energy_conservation.cpp`
-   - The hybrid test compares analytical vs RK4 energy, providing stronger validation
-
-2. **test_extreme_orientation.cpp: Polar (i=90°) & Retrograde (i=180°)** (REMOVED)
-   - Reason: Polar and retrograde boundary cases already covered by `test_precision_boundaries.cpp`
-   - Only "mixed: high inclination + high eccentricity" case retained
-   - Renamed to `test_extreme_orientation_mixed.cpp`
-
-3. **test_extreme_orientation.cpp: Original full scope** (REDUCED)
-   - Reason: Duplicate with existing test_precision_boundaries
-   - Polar orbit (i=π/2): Already tested in test_precision_boundaries
-   - Retrograde orbit (i=π): Already tested in test_precision_boundaries
-
-**Overlap Analysis:**
-
-**test_inclined_orbits.cpp** (Molniya: e=0.74, i=63.4°)
-- Overlaps: Extreme eccentricity, Extreme orientation
-- Gap: Need e=0.99+, retrograde (i>π/2), polar (i=π/2 exactly)
-- Note: Does NOT overlap with test_cartesian_to_elements_quadrature (tests opposite conversion direction)
-
-**test_moon_orbits.cpp** (Moon ~27 day period)
-- Overlaps: Extreme timescales
-- Gap: Need Mercury-like (~88 days), very slow (>10 years)
-
-**test_energy.cpp** (circular orbit energy)
-- Overlaps: Energy conservation tests
-- Gap: Need analytical propagation validation, method comparison
-- Note: test_energy_conservation_analytical removed; hybrid test covers this gap
-
-**test_orbital_period.cpp** (Earth 365 days, Mars 687 days)
-- Overlaps: Extreme timescales
-- Gap: Need <10 days, ~88 days, >3650 days
-
-**test_parabolic_orbit.cpp** (e=1.0)
-- Overlaps: Extreme eccentricity
-- Gap: Need e=0.99, e=0.9999, e=1.0001
-
-**test_hyperbolic_orbit.cpp** (e=1.5)
-- Overlaps: Extreme eccentricity
-- Gap: Need e=0.9999 near-parabolic boundary
-
-**test_maneuvers.cpp** (prograde/retrograde/normal burns)
-- Overlaps: Hybrid impulse burns
-- Gap: Need continuous thrust, Hohmann sequence, apsides burns
-
-**test_maneuver_planning.cpp** (time/true anomaly triggers)
-- Overlaps: Hybrid impulse burns
-- Gap: Need burns at apsides, Hohmann transfer
-
-### Config Sharing Opportunities
-
-**Can Share Configs (Partial Overlap):**
-1. **test_extreme_eccentricity** ↔ test_parabolic_orbit/hyperbolic_orbit
-    - Existing: e=1.0, 1.5
-    - New: e=0.99, 0.9999, 1.0001
-    - May need new config for e=0.99, 0.9999 cases
-
-2. **test_hybrid_impulse_burns** ↔ test_maneuvers
-    - Can reuse burn infrastructure
-    - New scenarios require separate config (Hohmann, apsides burns)
-
-3. **test_hybrid_energy_conservation** ↔ test_energy
-    - Different objectives (comparison vs. drift)
-    - Could share circular orbit config
-
-**Cannot Share Configs (Different Parameters):**
-1. **test_extreme_orientation_mixed** vs test_inclined_orbits
-    - Existing: i=1.107 (63.4°)
-    - New: Combined high inclination + high eccentricity (unique)
-
-2. **test_cartesian_to_elements_extreme** vs all existing
-    - New test category (no existing tests)
-
-3. **test_cartesian_to_elements_quadrature** vs test_inclined_orbits
-    - Tests opposite conversion direction (cartesian→elements vs elements→cartesian)
-    - Both needed for complete validation
-
-### Unique New Test Categories
-
-**Entirely New Functionality:**
-1. Cartesian to orbital elements conversion (Phase 1.1) - 3 tests
-2. Newton-Raphson solver convergence (Phase 1.2) - 1 test
-3. Analytical propagation accuracy (Phase 1.3) - 2 tests
-4. Hybrid continuous thrust integration (Phase 2.2) - 1 test
-5. Energy comparison: analytical vs. RK4 (Phase 2.3) - 1 test
-6. Propagation through apsides - 1 test
-
-**New Orbital Regimes:**
-7. Combined high inclination + high eccentricity - 1 test (reduced from 3 orientation tests)
-8. Extremely fast orbits (Mercury-like, <100 days) - 1 test
-9. Extremely slow orbits (>10 years) - 1 test
-10. Boundary values (e=0, i=π/2, i=π) - 1 test (already in test_precision_boundaries)
-
-### Minimal File Count with Sharing
-
-**Final estimate: 11 files** (reduced from 14)
-
-**Reductions applied:**
-- Removed test_energy_conservation_analytical.cpp (OPTIONAL, covered by hybrid test)
-- Removed duplicate polar/retrograde tests from test_extreme_orientation (covered by test_precision_boundaries)
-- Renamed to test_extreme_orientation_mixed.cpp (only tests combined high inclination + eccentricity)
-
-**Recommendation: Keep 11 files**
-- Each test has self-documenting config
-- Easier to debug isolated failures
-- Config reuse doesn't save much (configs are small)
-- Clear separation of concerns
-- No duplicate test coverage
+#### 6. ✅ test_precision_boundaries.cpp + .toml: Exact boundary value handling
 
 ## Implementation Priority
 
@@ -558,8 +155,8 @@ Total estimated test files: 11 (reduced from 14 after overlap analysis)
 8. ⬜ test_extreme_orientation_mixed.cpp (high inclination + high eccentricity)
 9. ⬜ test_extreme_timescales.cpp (fast/slow periods)
 10. ✅ test_precision_boundaries.cpp (exact values)
-11. ⬜ test_cartesian_to_elements_extreme.cpp (edge cases)
-12. ⬜ test_cartesian_to_elements_quadrature.cpp (cartesian→elements conversion)
+11. ✅ test_cartesian_to_elements_extreme.cpp (parabolic test fixed and tolerances tightened)
+12. ✅ test_cartesian_to_elements_quadrature.cpp (argument of periapsis fix)
 13. ✅ test_analytical_propagation_timesteps.cpp (large/small dt)
 
 ## Notes
@@ -567,8 +164,5 @@ Total estimated test files: 11 (reduced from 14 after overlap analysis)
 - Each .cpp file requires corresponding .toml config
 - Some test categories can share configs if parameters align
 - SOI transition tests deferred per user requirements
-- **Test count reduced from 14 to 11 after overlap analysis** (2026-02-01)
-- Removed tests:
-  - test_energy_conservation_analytical.cpp (OPTIONAL - covered by hybrid test)
-  - Duplicate polar/retrograde tests in test_extreme_orientation (covered by test_precision_boundaries)
-- Retained test_cartesian_to_elements_quadrature.cpp (validates NEW function, opposite direction of test_inclined_orbits)
+- Test count: 10/14 files fully passing (8/14 previously plus 2 new cartesian_to_elements tests)
+- Additional test added: test_barkers_equation.cpp (parabolic propagation, 11 tests)