latlong2

https://pub.dev/packages/latlong2
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latlong2 is a lightweight Dart library for common latitude and longitude calculations, supporting...
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### Calculate Offset Coordinate

Source: https://pub.dev/packages/latlong2

Shows how to find a new coordinate by offsetting a starting point by a given distance and bearing. The result can be printed in decimal degrees or sexagesimal format.

```dart
final Distance distance = const Distance();
final num distanceInMeter = (earthRadius * pi / 4).round();

final p1 = LatLng(0.0, 0.0);
final p2 = distance.offset(p1, distanceInMeter, 180);

// LatLng(latitude:-45.219848, longitude:0.0)
print(p2.round());

// 45° 13' 11.45" S, 0° 0' 0.00" O
print(p2.toSexagesimal());

```

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### Dart File Convention Check

Source: https://pub.dev/packages/latlong2/score

This snippet shows an example of a 'part-of' directive that uses a library name, which can be flagged by static analysis tools like lints_core. Ensure your part-of directives are correctly formatted.

```dart
part of latlong2;
```

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### Smooth a Path of Coordinates

Source: https://pub.dev/packages/latlong2

Illustrates how to smooth a list of geographical coordinates using the Catmull-Rom algorithm. The equalize method can be used to adjust the path with a specified number of steps.

```dart
// zigzag is a list of coordinates
final Path path = Path.from(zigzag);

// Result is below
final Path steps = path.equalize(8,smoothPath: true);

```

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### Apache License 2.0

Source: https://pub.dev/packages/latlong2

This code block contains the full text of the Apache License, Version 2.0, which governs the usage and distribution of the latlong2 library.

```text
Copyright 2015 Michael Mitterer (office@mikemitterer.at),
IT-Consulting and Development Limited, Austrian Branch

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
you may obtain a copy of the License at

   https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
either express or implied. See the License for the specific language
governing permissions and limitations under the License.

```

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### Add latlong2 to Dart Project

Source: https://pub.dev/packages/latlong2/install

Use this command to add the latlong2 package as a dependency in your Dart project.

```bash
$ dart pub add latlong2
```

--------------------------------

### Add latlong2 to Flutter Project

Source: https://pub.dev/packages/latlong2/install

Use this command to add the latlong2 package as a dependency in your Flutter project.

```bash
$ flutter pub add latlong2
```

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### Calculate Distance Between Two Coordinates

Source: https://pub.dev/packages/latlong2

Demonstrates how to calculate the distance between two geographical points in kilometers or meters using the Distance class. Ensure the LatLng class is imported.

```dart
final Distance distance = Distance();

// km = 423
final double km = distance.as(LengthUnit.Kilometer,
    LatLng(52.518611, 13.408056), LatLng(51.519475, 7.46694444));

// meter = 422591.551
final double meter = distance(
  LatLng(52.518611, 13.408056),
  LatLng(51.519475, 7.46694444),
);

```

--------------------------------

### Import latlong2 Classes in Dart Code

Source: https://pub.dev/packages/latlong2/install

Import the necessary classes from the latlong2 package into your Dart files to use its functionalities.

```dart
import 'package:latlong2/latlong.dart';
import 'package:latlong2/latlong/Circle.dart';
import 'package:latlong2/latlong/Distance.dart';
import 'package:latlong2/latlong/LatLng.dart';
import 'package:latlong2/latlong/LengthUnit.dart';
import 'package:latlong2/latlong/Path.dart';
import 'package:latlong2/latlong/calculator/Haversine.dart';
import 'package:latlong2/latlong/calculator/Vincenty.dart';
import 'package:latlong2/latlong/interfaces.dart';
import 'package:latlong2/spline.dart';
import 'package:latlong2/spline/CatmullRomSpline.dart';
```

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### Calculate Distance Between Two Coordinates

Source: https://pub.dev/packages/latlong2/example

Calculates the distance between two geographical points in kilometers and meters. Ensure the 'latlong2' package is imported.

```dart
import 'package:latlong2/latlong.dart';

const EARTH_RADIUS = 6371000.0;

void main() {
  var distance = Distance();

  // km = 423
  final km = distance.as(LengthUnit.Kilometer, LatLng(52.518611, 13.408056),
      LatLng(51.519475, 7.46694444));

  // meter = 422591.551
  final meter = 
      distance(LatLng(52.518611, 13.408056), LatLng(51.519475, 7.46694444));

  print('km: $km, meter: $meter');

  distance = const Distance();
  final num distanceInMeter = (earthRadius * pi / 4).round();

  final p1 = LatLng(0.0, 0.0);
  final p2 = distance.offset(p1, distanceInMeter, 180);

  // LatLng(latitude:-45.219848, longitude:0.0)
  print(p2.round());

  // 45° 13' 11.45" S, 0° 0' 0.00" O
  print(p2.toSexagesimal());

  //create a new distance calculator with Haversine algorithm
  distance = const Distance(calculator: Haversine());

  //create coordinates with NaN or Infinity state to check if the distance is calculated correctly
  final point1 = LatLng(double.nan, 0.0);
  final point2 = distance.offset(point1, distanceInMeter, 180);

  var meterDistance = distance.as(LengthUnit.Meter, point1, point2);
  print(meterDistance);
}
```
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