A transparent corridor proximity calculation.
A repeatable answer to a narrow question: which fictional assets are within a chosen distance of a straight corridor? These are invented metre coordinates, not Ugandan road data.
One corridor, three fictional assets.
The example corridor goes from (0, 0) to (1000, 0) in a made-up planar system whose axes are measured in metres. Clinic A is at (150, 120), School B at (450, 390) and Facility C at (700, 80). Because the corridor is horizontal and all perpendicular projections fall within the segment, distances are exactly 120, 390 and 80 metres.
Synthetic dataset: None of these points represent actual clinics, schools, roads or geographic coordinates. The example illustrates geometric distance, not travel-time, flood exposure or a certified spatial impact report.
Change the distance threshold.
| Fictional asset | Distance | Within threshold? |
|---|---|---|
| Clinic A | 120 m | Yes |
| School B | 390 m | No |
| Facility C | 80 m | Yes |
2 of 3 fictional assets within 200 m.
For point P and line segment A–B, project P onto the line, clamp the projection parameter between 0 and 1, then measure Euclidean distance to that nearest point. The source handles both segment endpoints and zero-length line segments.
What a real corridor study additionally requires.
- A properly projected CRS with metre units; latitude and longitude degrees cannot be used directly as metric distances.
- Complete, validated road or corridor geometry; this one-segment teaching example is not a network model.
- Source authority, licensing, asset IDs, dates and georeferenced inputs.
- Correct buffer or overlay topology where polygons, complex corridors and GIS feature attributes matter.
- Saved and independently reopened GeoPackage or database outputs, with tested feature counts and acceptance criteria.
Real use cases need real validation.
Transparent arithmetic is the first step, not proof of geographic correctness or readiness for high-stakes decisions.