phpgeo provides abstractions to geographical coordinates (including support for different ellipsoids) and allows you to calculate geographical distances between coordinates with high precision.

• phpgeo - A Simple Geo Library for PHP
  • Table of Contents
  • Requirements
  • Documentation
  • Installation
  • License
  • Features
  • Examples/Usage
    • Distance between two points (Vincenty's Formula)
    • Simplifying a polyline
    • Polygon contains a point (e.g. "GPS geofence")
    • Formatted output of coordinates
      • Decimal Degrees
      • Degrees/Minutes/Seconds (DMS)
      • GeoJSON
  • Development
    • Run Tests
  • Miscellaneous
  • Credits

Minimum required PHP version is 7.3. phpgeo fully supports PHP 8.

The 3.x releases require PHP >= 7.2 but don't get feature updates any longer. Bugfixes will be backported.

The 2.x releases require PHP >= 7.0 but don't get feature updates any longer. Bugfixes won't be backported.

The 1.x release line has support for PHP >= 5.4. Bugfixes won't be backported.

The documentation is available at https://phpgeo.marcusjaschen.de/

API documentation is available as well: https://phpgeo.marcusjaschen.de/api/

Using Composer, just add it to your composer.json by running:

composer require mjaschen/phpgeo

Update the version constraint in the project's composer.json and run composer update or require the new version by running:

composer require mjaschen/phpgeo:^4.0

Starting with version 2.0.0 phpgeo is licensed under the MIT license. Older versions were GPL-licensed.

Info: Please visit the documentation site for complete and up-to-date documentation with many examples!

phpgeo provides the following features (follow the links for examples):

• abstractions of several geometry objects (point, line, polyline/GPS track, polygon
• support for different ellipsoids, e.g. WGS-84
• length/distance/perimeter calculations with different implementations (Haversine, Vincenty)
• Geofence calculation, i. e. answering the question "Is this point contained in that area/polygon?"
• formatting and output of geometry objects (GeoJSON, nice strings, e. g. 18° 54′ 41″ -155° 40′ 42″)
• calculation of bearing angle between two points (spherical or with Vincenty's formula)
• calculation of a destination point for a given starting point, bearing angle, and distance (spherical or with Vincenty's formula)
• calculation of the perpendicular distance between a point and a line
• calculation of the Cardinal Distances between two points
• getting segments of a polyline /polygon,
• reversing direction of polyline/polygon

This list is incomplete, please visit the documentation site for the full monty of documentation and examples!

Use the calculator object directly:

<?php

use Location\Point;
use Location\Distance\Vincenty;

$coordinate1 = new Point(19.820664, -155.468066); // Mauna Kea Summit
$coordinate2 = new Point(20.709722, -156.253333); // Haleakala Summit

$calculator = new Vincenty();

echo $calculator->getDistance($coordinate1, $coordinate2); // returns 128130.850 (meters; ≈128 kilometers)

or call the getDistance() method of a Point object by injecting a calculator object:

<?php

use Location\Point;
use Location\Distance\Vincenty;

$coordinate1 = new Point(19.820664, -155.468066); // Mauna Kea Summit
$coordinate2 = new Point(20.709722, -156.253333); // Haleakala Summit

echo $coordinate1->getDistance($coordinate2, new Vincenty()); // returns 128130.850 (meters; ≈128 kilometers)

Polylines can be simplified to save storage space or bandwidth. Simplification is done with the Ramer–Douglas–Peucker algorithm (AKA Douglas-Peucker algorithm).

<?php

use Location\Point;
use Location\Polyline;
use Location\Distance\Vincenty;

$polyline = new Polyline();
$polyline->addPoint(new Point(10.0, 10.0));
$polyline->addPoint(new Point(20.0, 20.0));
$polyline->addPoint(new Point(30.0, 10.0));

$processor = new Simplify($polyline);

// remove all points which perpendicular distance is less
// than 1500 km from the surrounding points.
$simplified = $processor->simplify(1500000);

// simplified is the polyline without the second point (which
// perpendicular distance is ~1046 km and therefore below
// the simplification threshold)

phpgeo has a polygon implementation which can be used to determinate if a point is contained in it or not. A polygon consists of at least three points. Points are instances of the Point class.

Warning: The calculation gives wrong results if the polygons has points on both sides of the 180/-180 degrees meridian.

<?php

use Location\Point;
use Location\Polygon;

$geofence = new Polygon();

$geofence->addPoint(new Point(-12.085870,-77.016261));
$geofence->addPoint(new Point(-12.086373,-77.033813));
$geofence->addPoint(new Point(-12.102823,-77.030938));
$geofence->addPoint(new Point(-12.098669,-77.006476));

$outsidePoint = new Point(-12.075452, -76.985079);
$insidePoint = new Point(-12.092542, -77.021540);

var_dump($geofence->contains($outsidePoint)); // returns bool(false) the point is outside the polygon
var_dump($geofence->contains($insidePoint)); // returns bool(true) the point is inside the polygon

You can format a pair of coordinates (i.e. an instance of Point) in different styles.

<?php

use Location\Point;
use Location\Formatter\Coordinate\DecimalDegrees;

$coordinate = new Point(19.820664, -155.468066); // Mauna Kea Summit

echo $coordinate->format(new DecimalDegrees());

<?php

use Location\Point;
use Location\Formatter\Coordinate\DMS;

$coordinate = new Point(18.911306, -155.678268); // South Point, HI, USA

$formatter = new DMS();

echo $coordinate->format($formatter); // 18° 54′ 41″ -155° 40′ 42″

$formatter->setSeparator(", ")
    ->useCardinalLetters(true)
    ->setUnits(DMS::UNITS_ASCII);

echo $coordinate->format($formatter); // 18° 54' 41" N, 155° 40' 42" W

<?php

use Location\Point;
use Location\Formatter\Coordinate\GeoJSON;

$coordinate = new Point(18.911306, -155.678268); // South Point, HI, USA

echo $coordinate->format(new GeoJSON()); // { "type" : "point" , "coordinates" : [ -155.678268, 18.911306 ] }

Before submitting a pull request, please be sure to run all checks and tests and ensure everything is green.

• lint PHP files for syntax errors: composer ci:lint
• run static analysis with Psalm and report errors: composer ci:psalm
• run unit tests with PHPUnit: composer ci:tests

To run all checks and tests at once, just use composer ci.

Of course, it's possible to use the test runners directly, e.g. for PHPUnit:

./vendor/bin/phpunit

Psalm:

./vendor/bin/psalm

@clemdesign created a TypeScript port of phpgeo.

• Marcus Jaschen [email protected]
• Chris Veness - JavaScript implementation of the Vincenty formula for distance calculation
• Ersts,P.J., Horning, N., and M. Polin[Internet] Perpendicular Distance Calculator(version 1.2.2) Documentation. American Museum of Natural History, Center for Biodiversity and Conservation. Available from http://biodiversityinformatics.amnh.org/open_source/pdc. Accessed on 2013-07-07.
• W. Randolph Franklin, PNPOLY - Point Inclusion in Polygon Test Documentation
• Richard Barnes Polyline GeoJSON Formatter
• Paul Vidal Polygon Implementation