nx_geo_match.nx

nx_geo_match.nx -- LIB: GEO-023 MAP-MATCHING (snap a noisy GPS fix to a road network). For each road EDGE (a segment A->B) we project the GPS point P onto the segment (closest point), clamped to the endpoints, then pick the edge whose snapped point is nearest P. Projection parameter t = dot(P-A, B-A) / dot(B-A, B-A) clamped to [0,1]; the snapped point is A + t*(B-A). THE EXCEED ANGLE: the projection + nearest-edge choice are INTEGER and deterministic -- the snapped position and the chosen edge are reproducible to the bit (no float jitter that makes a GPS fix flip between two near-equidistant roads). Overflow-safe at any scale: the t fraction (num,den) is normalized (lockstep >>1, ratio preserved) before multiplying by the edge delta, exactly as the GEO-015 clip intersection does. Sovereign + offline; the road graph is seeded data, not a service. Convention: points/edges in microdegrees, [lat,lon]; edges = flat [alat,alon,blat,blon, ...]. license_tier: ORIGINAL