geodesy 0.6.0

A Dart library for geodesic and trigonometric calculations working with points and paths

Geodesy

A Dart library for implementing geodesic and trigonometric calculations based on a spherical Earth model for working with points and paths such as distances, bearings and destinations

Getting Started

Add the following line in your pubspec.yml file

geodesy:<latest_version>

Include the widget in your dart file

import 'package:geodesy/geodesy.dart';

Usage

Geodesy()

final Geodesy geodesy = Geodesy();

LatLng(double latitude, double longitude)

final LatLng l = LatLng(22.308, 114.1716);

Methods

destinationPointByDistanceAndBearing(LatLng l, num distance, num bearing, [num radius])

Calculate a destination point given the distance and bearing. If radius is not specified, Earth radius will be used.

final LatLng destinationPoint = geodesy.destinationPointByDistanceAndBearing(l3, 2400, 420.2);

midPointBetweenTwoGeoPoints(LatLng l1, LatLng l2)

Calculate the midpoint between teo geo points.

final LatLng midpoint = geodesy.midPointBetweenTwoGeoPoints(l1, l2);

distanceBetweenTwoGeoPoints(LatLng l1, LatLng l2, [num radius])

Calculate the distance in meters between two geo points. If radius is not specified, Earth radius will be used.

final num distance = geodesy.distanceBetweenTwoGeoPoints(l1, l2);

bearingBetweenTwoGeoPoints(LatLng l1, LatLng l2)

Calculate the bearing from point l1 to point l2.

final num finalBearing = geodesy.finalBearingBetweenTwoGeoPoints(l1, l2);

finalBearingBetweenTwoGeoPoints(LatLng l1, LatLng l2)

Calculate the final bearing from point l1 to point l2.

final num finalBearing = geodesy.finalBearingBetweenTwoGeoPoints(l1, l2);

degreesToRadians(num degrees)

Convert degrees to radians

final num l1LatRadians = degreesToRadians(l1.lat);

radiansToDegrees(num radians)

Convert degrees to radians

final num degrees = radiansToDegrees(latRadians);

isGeoPointInBoundingBox(LatLng l, LatLng topLeft, LatLng bottomRight)

Check if a given geo point is in the bounding box

final bool inBoundingBox = geodesy.isGeoPointInBoundingBox(l1, l2, l3);

intersectionByPaths(LatLng l1, LatLng l2, num b1, num b2)

Calculate the geo point of intersection of two given paths

final LatLng intersectionByPaths = geodesy.intersectionByPaths(l1, l2, b1, b2);

crossTrackDistanceTo(LatLng l1, LatLng start, LatLng end, [num radius])

Calculate signed distance from a geo point to create circle with start and end points

final num distanceToGreatCircle = geodesy.crossTrackDistanceTo(l1, l2, l3);

isGeoPointInPolygon(LatLng l, List

Check if a given geo point is in the a polygon using even-odd rule algorithm

final bool isGeoPointInPolygon = geodesy.isGeoPointInPolygon(l, poly);

pointsInRange(LatLng point, List

Get a list of points within a distance in meters from a given point

final point = LatLng(51.0, 0);
final pointsToCheck = <LatLng>[/* points here */];
final distance = 10000;
List<LatLng> geoFencedPoints = geodesy.pointsInRange(point, pointsToCheck, distance);

getRectangleBounds(List

Similar to PolygonEnvelop in Python

  List<LatLng> polygonCoords = [
    const LatLng(37.7749, -122.4194),
    const LatLng(37.3382, -121.8863),
    const LatLng(37.7749, -121.4194),
    const LatLng(37.7749, -123.4194),
  ];

  List<LatLng> rectangleBounds = geodesy.getRectangleBounds(polygonCoords);

greatCircleDistanceBetweenTwoGeoPoints(num lat1, num lng1, num lat2, num lng2)

Calculate the Great-Circle Distance between two Geo points using the Haversine formula

num latitude1 = 37.7749;
num longitude1 = -122.4194;
num latitude2 = 37.3382;
num longitude2 = -121.8863;

num greatCircleDistance = geodesy.greatCircleDistanceBetweenTwoGeoPoints(
    latitude1, longitude1, latitude2, longitude2);

calculateBoundingBox(LatLng centerPoint, num distanceInKm)

Given the Latitude and Longitude and distance in kilometers it calculate the bounding box value

  final centerPoint = const LatLng(
      37.7749, -122.4194); // Example central position (San Francisco)

  final distanceInKm = 1.0; // Example distance in kilometers

  final boundingBox = geodesy.calculateBoundingBox(centerPoint, distanceInKm);

findPolygonCentroid(List

  List<LatLng> polygon = [
    const LatLng(0, 0),
    const LatLng(4, 0),
    const LatLng(4, 4),
    const LatLng(0, 4)
  ];

  LatLng centroid = geodesy.findPolygonCentroid(polygon);
  print("Centroid: ${centroid.latitude}, ${centroid.longitude}");

getPolygonIntersection(List

final List<LatLng> polygon1 = [
    const LatLng(0, 0),
    const LatLng(0, 2),
    const LatLng(2, 2),
    const LatLng(2, 0),
  ];

  final List<LatLng> polygon2 = [
    const LatLng(1, 1),
    const LatLng(1, 3),
    const LatLng(3, 3),
    const LatLng(3, 1),
  ];

  final List<LatLng> intersectionPoints =
      geodesy.getPolygonIntersection(polygon1, polygon2);

  print('Intersection Points:');
  for (final point in intersectionPoints) {
    print('Latitude: ${point.latitude}, Longitude: ${point.longitude}');
  }