fix: add fallback mutation for small routes in GA crossover#196
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arybhatt4533 wants to merge 1 commit into52North:mainfrom
Open
fix: add fallback mutation for small routes in GA crossover#196arybhatt4533 wants to merge 1 commit into52North:mainfrom
arybhatt4533 wants to merge 1 commit into52North:mainfrom
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Description:
This PR addresses stability issues and potential crashes in the Genetic Algorithm crossover operators (SinglePointCrossover and TwoPointCrossover) when dealing with short routes.
Key Changes:
Introduced fallback_mutate: Added a safety mechanism in OffspringRejectionCrossover. When a route is too small for a standard crossover (e.g., < 3 waypoints for SP or < 6 for TP), the algorithm now applies a small random mutation instead of returning identical parents or crashing.
Fixed Coordinate Slicing: Ensured that only Latitude and Longitude (0:2) are passed to the patchfn.patch method. This prevents errors when waypoints contain additional data like speed or time.
Type Casting Safety: Added .astype(float) in the mutation logic to prevent NumPy UFuncOutputCastingError when performing arithmetic operations on integer-based test arrays.
Boundary Protection: Updated np.random.randint ranges to strictly avoid modifying start and end waypoints, ensuring route integrity.
Verification:
Tested with routes of size 2 (triggered SP fallback).
Tested with routes of size 4 (triggered TP fallback).
Verified that no CastingError occurs during coordinate perturbation.