GeoCoordinate

a utility Library to create and work with GeoCoordinates

Description

A tiny library to help you gettting things done with geospatial coordinates.

Installation

npm install geocoordinate

Usage

const {
    GeoCoordinate,
    BoundingBox
} = require('geocoordinate');

const brandenburgerTor = new GeoCoordinate([52.51626877497768, 13.377935641833488]);
const coord200mToNorth = brandenburgerTor.pointAtDistance(200, 0); // instance of GeoCoordinate: { coordinate: [ 52.518067418189524, 13.377935641833488 ] }

const potsdamerPlatz = new GeoCoordinate({
    latitude: 52.50947253231671,
    longitude: 13.37661188095808
});
brandenburgerTor.distanceTo(potsdamerPlatz); // 761.6555386291442
                                             // Distance in meters

const westminsterAbbay = new GeoCoordinate(51.499382976649365, -0.12724540716209276);

brandenburgerTor.quickDistanceTo(westminsterAbbay); // 932075.8108608712
brandenburgerTor.preciseDistanceTo(westminsterAbbay); // 930681.893582993


const oldBbox = new BoundingBox(); // Old way to instantiate BoundingBox, see below for more convenient method
bbox.pushCoordinate(52.51626877497768, 13.377935641833488);
bbox.pushCoordinate(51.499382976649365, -0.12724540716209276);

const newBbox = BoundingBox.fromCoordinates([52.51, 13.37], [51.49, -0.12])

newBbox.box();
/* {
    topLeftLatitude: 52.51,
    topLeftLongitude: -0.12,
    bottomRightLatitude: 51.49,
    bottomRightLongitude: 13.37
} */

newBbox.contains(52.50947253231671, 13.37661188095808); // true

oldBbox.centerLatitude();
// 52.00782587581352
oldBbox.centerLongitude();
// 6.625345117335698

API

GeoCoordinate

constructor

Usage:

new GeoCoordinate([1,1]);
new GeoCoordinate(32, 17.4);
new GeoCoordinate(62.1, 24.3, 70); // Altitude = 70m
new GeoCoordinate({
    latitude: 6,
    longitude: 18
});

.asArray()

Returns array [latitude, longitude[, altitude]].

.sortArrayByReferencePoint(arr)

Sorts arr in place by distance to reference point.

const potsdamerPlatz = new GeoCoordinate({
    latitude: 52.50947253231671,
    longitude: 13.37661188095808
});

const arr = [
    [51, 23],
    {latitude: 54, longitude: 16},
    new GeoCoordinate(64, 32)
];
potsdamerPlatz.sortArrayByReferencePoint(arr);
// arr is sorted now

.quickDistanceTo(point)

Calculates quickly distance from this to point. Not recommended for long distances. Returns meters.

.preciseDistanceTo(point)

Calculates precise distance from this to point. Returns meters.

.distance3DTo(point)

Calculates a distance between two points, assuming they are on a plain area, correcting by actual latitude distortion. Will produce bad results for long distances (>>500km) and points very close to the poles.

.pointAtDistance(distance, angle)

Calculates the coordinate that is a given number of meters from this coordinate at the given angle

• @param {number} distance the distance in meters the new coordinate is way from this coordinate.
• @param {number} bearing the angle in degrees at which the new point will be from the old point. In radians, clockwise from north.
• @returns {GeoCoordinate} a new instance of this class with only the latitude and longitude set.

.bearingRadTo(distance, angleInRadians)

The same as .pointAtDistance but angle is given in radians.

.latitude()

Returns latitude of current point

.longitude()

Returns longitude of current point

.altitude()

Return altitude of the point or 0.

BoundingBox

constructor

Constructor doesn't take arguments.

const bb = new BoundingBox();
bb.pushCoordinate(52.51626877497768, 13.377935641833488);
bb.pushCoordinate({latitude: 44, longitude: 6});

fromCoordinates

const bbox = BoundingBox.fromCoordinates([32, 53], [33, 54]);

.contains(point)

Checks if point is contained in bounding box.

const bbox = BoundingBox.fromCoordinates([32, 53], [33, 54]);
bbox.contains(new GeoCoordinate(23, 44));
bbox.contains([32.5, 54.5]);