GIS / spatial interface¶

epistemic-graph carries a native geospatial modality — a pure-Rust eg-geo crate (geo/geo-types + an in-house packed Hilbert / STR R-tree; no GEOS / PROJ C deps) behind the geo feature (folded into in the one main build). Geometries persist as a typed value in the redb per-graph store, a durable R-tree indexes them, and spatial predicates compose with graph traversal / vector / SQL in one plan. GeoSPARQL surfaces it over SPARQL; SQL ST_* functions surface it over pgwire.

Status snapshot: geometry model + WKT/WKB/GeoJSON/GPX I/O (EG-KG.ontology.singles-concept/257/264) — plus Shapefile/KML/ GeoParquet (EG-KG.domains.geo-formats) — DE-9IM + RCC8/Egenhofer relations (EG-KG.ontology.de-9im-relations/155), constructive algebra (EG-KG.ontology.concept-9), CRS + reprojection + geodesic distance (EG-KG.domains.coordinate-reference-system/262/256), a durable R-tree index (EG-KG.domains.spatial-strtree-index), map tiles (EG-KG.domains.map-tiles), routing/isochrones/TSP (EG-KG.domains.geo-routing) with turn-restrictions + time-windows (EG-KG.domains.geo-partitioning), and map-based task tracking (EG-KG.domains.geo-task) are shipped. See the capability matrix.

Geometry model (EG-KG.ontology.singles-concept/257)¶

The full OGC geometry set: Point, LineString, Polygon (with interior rings / holes), MultiPoint, MultiLineString, MultiPolygon, and GeometryCollection, with EWKT parse/serialize. Stored as a typed redb value with a per-shard durable R-tree (EG-KG.domains.spatial-strtree-index) consulted by Op::SpatialScan for selectivity.

Format I/O (EG-KG.domains.geojson-gpx-formats/306)¶

Reader/writer for GeoJSON (Feature / FeatureCollection), WKB (binary geometry), and GPX tracks — round-tripping eg-geo geometries. Program B completes the map-data ingest/export matrix with ESRI Shapefile (.shp/.dbf/.shx), KML/KMZ, and GeoParquet (EG-KG.domains.geo-formats), round-tripping geometries and their attributes — so field data from GIS tooling (QGIS/ArcGIS exports, Google Earth KML, columnar GeoParquet lakes) loads and exports directly.

Predicates & relations (EG-KG.ontology.de-9im-relations/155)¶

Core (EG-KG.ontology.singles-concept): within / intersects / dwithin as Pred::SpatialWithin / SpatialDWithin.
DE-9IM (EG-KG.ontology.de-9im-relations): the full relation matrix — contains / covers / touches / crosses / overlaps / equals / disjoint, as additional Pred::Spatial* variants.
RCC8 + Egenhofer (EG-KG.ontology.concept-7): the OGC topological-relation families, lowered onto the DE-9IM intersection matrix (surfaced through GeoSPARQL, see below).

Constructive algebra (EG-KG.ontology.concept-9)¶

Buffer, convex hull, union / intersection / difference, simplify, and centroid — the constructive ops for urban-planning / logistics — executed via Op::SpatialOp { kind } in eg-plan (pure-Rust).

CRS, reprojection & geodesics (EG-KG.domains.coordinate-reference-system/262/256)¶

A coordinate-reference-system registry (crs module — EPSG codes incl. 4326 WGS84 / 3857 Web-Mercator + proj params) and pure-Rust reprojection (geographic ↔ Web-Mercator + affine / Helmert), so geometries carry a CRS and ST_Transform / GeoSPARQL CRS-URIs reproject correctly — no PROJ C dependency. A geometry's CRS tag selects planar-vs-geodesic distance: great-circle / Haversine + Vincenty distance and geodesic area (EG-KG.ontology.concept-8) give accurate real-world measures for logistics / urban planning.

Map tiling (EG-KG.domains.map-tiles)¶

Slippy-map tile addressing (XYZ / TMS z/x/y ↔ lon/lat/bbox via Web-Mercator) + Mapbox Vector Tile (MVT protobuf-lite) encoding of features clipped to a tile, so a web map (Leaflet / MapLibre) renders the graph's spatial data.

Routing, isochrones & TSP (EG-KG.domains.geo-routing/312)¶

Graph routing over a spatial network: weighted shortest path (Dijkstra / A with a geo heuristic), isochrones (reachability within a cost budget), and a nearest-neighbour + 2-opt TSP tour — the logistics / urban-planning primitives, reusing the engine's graph traversal. Program B extends the router for realistic logistics* (EG-KG.domains.geo-partitioning):

Turn restrictions — per-turn penalties (via an edge/turn cost), so a banned or costly turn is avoided; one-way edges were already supported.
Time-windows / time-dependent weights — an edge weight can be a function of departure time, so rush-hour congestion or time-restricted access is modelled and the shortest path depends on when you leave.

Map-based task tracking (EG-KG.domains.geo-task)¶

Geo-anchored tasks: a :GeoTask node with a location + status + optional service-area geometry, spatial queries (tasks within a bbox / polygon, nearest-N to a point, tasks along a route), and assignment to the nearest resource — the field-ops / urban-planning task layer over the spatial store.

Reaching it¶

SQL (pgwire / in-engine): st_within / st_distance / ST_Transform etc. compose with the node store — see sql.
GeoSPARQL (feature geosparql): the geo: / geof: vocab, WKT/GML literals, and sfWithin/sfIntersects/distance + the RCC8/Egenhofer function families — see sparql.
UQL: Op::SpatialScan / Op::SpatialOp are first-class planner ops, so a spatial filter composes with Traverse/Rank/Filter in one UQL pipeline.