Point

A position on Earth in WGS84: its latitude and longitude by name, and its height above the ellipsoid where it has one. Sent as a GeoJSON Point, shown 51.5072° N, 0.1276° W.

Geospatial; not ordered; since Jadpo 0.1.0.

Make one

Build one from its fields, Point { latitude: ... longitude: ... }.

These operations give one: geo.centroid, geo.from_lat_lng and geo.from_lng_lat.

Fields

Text, JSON and storage

It has no single text form, so text.from and text.parse don't take it. JSON sends a GeoJSON geometry, its positions longitude first.

It is stored in one column named for the field, of type geography. {"type":"Point","coordinates":[0,0]} is stored as 'SRID=4326;POINT (0 0)'::geography.

Shown to people

text.format(value, locale:) shows it to people in their locale.

With locale: Locale.en_gb:

Operations

• geo.bearing(from: Point, to: Point) -> Bearing: The direction the geodesic leaves from in, in degrees clockwise from true north, at least 0 and below 360, to 9 places. Two equal points have none: the call fails with same_point, which its attempt maps.
• geo.bounding_box(shape: T) -> BoundingBox: The smallest box of parallels and meridians holding the shape, an edge's highest or lowest point counted, across the antimeridian when that box is narrower; a shape holding a pole runs from -180 to 180.
• geo.centroid(shape: T) -> Point: The shape's centre on the sphere, as PostGIS's ST_Centroid(x, false) finds it: each point a unit vector, weighted by area, length or count by the shape's kind, summed, and back to latitude and longitude. It may lie outside a concave polygon.
• geo.contains(a: T, b: U) -> Bool: Whether no point of b lies outside a, edges included. a may be a BoundingBox, whose sides are compared directly, or a Circle, holding the points within its radius of its centre.
• geo.distance(from: Point, to: Point) -> Length: The geodesic distance between two points on the ellipsoid, rounded half to even to the micrometre.
• geo.from_lat_lng(numbers: List<Number>) -> Point: The Point two numbers give, latitude first, as [51.5072, -0.1276], or three, the third its altitude in metres. A latitude past 90 or a longitude past 180 fails with out_of_range, and any other count of numbers with malformed, which the call's attempt maps.
• geo.from_lng_lat(numbers: List<Number>) -> Point: The Point two numbers give, longitude first, as GeoJSON writes a position, [-0.1276, 51.5072], or three, the third its altitude in metres. A longitude past 180 or a latitude past 90 fails with out_of_range, and any other count of numbers with malformed, which the call's attempt maps.
• geo.intersects(a: T, b: U) -> Bool: Whether the two share at least one point, edges included.
• geo.to_wkt(shape: T) -> Text: The shape as WKT, longitude first, as PostGIS's ST_AsText writes it: POINT(-0.1276 51.5072), POINT Z (-0.1276 51.5072 35) with an altitude, each ring in the order it holds its points.
• geo.within(a: T, b: U, distance: Length?) -> Bool: geo.contains(b, a); or, with distance:, whether two points are at most that far apart, as geo.distance measures them.

Like every standard type, it also has the contract's own operations: text.format, json.read, json.write and ==. It isn't ordered, so < and sorting don't take it. Every standard type meets one contract says how they work.