• CHANGELOG.md
• Example
• Installing
• Versions
• 71

# Great-circle distance

Calculate the great-circle distance between two points (having Latitude,Longitude) on the surface of Earth You can get the distance using the Spherical law of cosines, Haversine formula or Vincenty`s formula

The great-circle distance is the shortest distance between two points on the surface of a sphere

A diagram illustrating great-circle distance (drawn in red) between two points on a sphere, P and Q. Two antipodal points, u and v, are also depicted.

By CheCheDaWaff (Own work) [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

Included in this library:

• Spherical law of cosines
• Haversine formula
• Vincenty` formula (por from the Android implementation)

`Disclaimer`: The earth is not quite a sphere. This means that errors(0.3%,0.5% errors) from assuming spherical geometry might be considerable depending on the points; so: `don't trust your life on this value`

Usage example:

``````final lat1 = 41.139129;
final lon1 = 1.402244;

final lat2 = 41.139074;
final lon2 = 1.402315;

var gcd = new GreatCircleDistance.fromDegrees(latitude1: lat1, longitude1: lon1, latitude2: lat2, longitude2: lon2);

print('Distance from location 1 to 2 using the Haversine formula is: \${gcd.haversineDistance()}');
print('Distance from location 1 to 2 using the Spherical Law of Cosines is: \${gcd.sphericalLawOfCosinesDistance()}');
print('Distance from location 1 to 2 using the Vicenty`s formula is: \${gcd.vincentyDistance()}');
``````

Check Wikipedia for detailed description on Great-circle distance

# Changelog #

## 0.0.1 #

• Initial version for the great-circle distance (Spherical law of cosines, Haversine formula and Vincenty` formula)

## 0.0.2 #

• Minor update to sample code

## 0.0.5 #

• Update descriptions

## 0.0.6 #

• Minor test update, added travis integration

## 1.0.0 #

Added coordinates validation. A coordinate is considered invalid if it meets at least one of the following criteria:

• Its latitude is greater than 90 degrees or less than -90 degrees.
• Its longitude is greater than 180 degrees or less than -180 degrees.

## 1.0.1 #

Remove upper bound Dart SDK constraint

thanks to @bramvbilsen for pointing it out and for the PR

example/great_circle_distance_example.dart

``````import 'package:great_circle_distance/great_circle_distance.dart';

main() {
final lat1 = 41.139129;
final lon1 = 1.402244;

final lat2 = 41.139074;
final lon2 = 1.402315;

var gcd = new GreatCircleDistance.fromDegrees(
latitude1: lat1, longitude1: lon1, latitude2: lat2, longitude2: lon2);

print(
'Distance from location 1 to 2 using the Haversine formula is: \${gcd.haversineDistance()}');
print('Distance from location 1 to 2 using the Spherical Law of Cosines is: \${gcd
.sphericalLawOfCosinesDistance()}');
print(
'Distance from location 1 to 2 using the Vicenty`s formula is: \${gcd.vincentyDistance()}');
}
``````

## Use this package as a library

### 1. Depend on it

``````
dependencies:
great_circle_distance: ^1.0.1

``````

### 2. Install it

You can install packages from the command line:

with pub:

``````
\$ pub get

``````

with Flutter:

``````
\$ flutter packages get

``````

Alternatively, your editor might support `pub get` or `flutter packages get`. Check the docs for your editor to learn more.

### 3. Import it

Now in your Dart code, you can use:

``````
import 'package:great_circle_distance/great_circle_distance.dart';
``````
1.0.1 Feb 8, 2018
1.0.0 Oct 12, 2017
0.0.6 Oct 7, 2017
0.0.5 Oct 7, 2017
0.0.4 Oct 7, 2017
0.0.3 Oct 1, 2017
0.0.2 Oct 1, 2017
0.0.1 Oct 1, 2017
 Popularity: Describes how popular the package is relative to other packages. [more] 77 Health: Code health derived from static analysis. [more] 56 Maintenance: Reflects how tidy and up-to-date the package is. [more] 79 Overall: Weighted score of the above. [more] 71

We analyzed this package on Apr 25, 2019, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

• Dart: 2.2.0
• pana: 0.12.14

#### Platforms

Detected platforms: Flutter, web, other

No platform restriction found in primary library `package:great_circle_distance/great_circle_distance.dart`.

#### Health issues and suggestions

Fix `lib/src/great_circle_distance_base.dart`. (-25.38 points)

Analysis of `lib/src/great_circle_distance_base.dart` failed with 1 error, 1 hint:

line 61 col 68: Undefined name 'PI'.

line 1 col 8: Unused import: 'dart:math'.

Fix `lib/src/formula/spherical_lawofcosines.dart`. (-25 points)

Analysis of `lib/src/formula/spherical_lawofcosines.dart` failed with 1 error:

line 10 col 49: Undefined name 'PI'.

Format `lib/great_circle_distance.dart`.

Run `dartfmt` to format `lib/great_circle_distance.dart`.

Format `lib/src/formula/harvesine.dart`.

Run `dartfmt` to format `lib/src/formula/harvesine.dart`.

Format `lib/src/formula/vincenty.dart`.

Run `dartfmt` to format `lib/src/formula/vincenty.dart`.

#### Maintenance suggestions

Package is getting outdated. (-20.55 points)

The package was last published 62 weeks ago.

#### Dependencies

Package Constraint Resolved Available
Direct dependencies
Dart SDK >=1.20.1 <3.0.0
Dev dependencies
test ^0.12.0