Table of Contents
- phpgeo - A Simple Geo Library for PHP
phpgeo provides abstractions to geographical coordinates (including support for different ellipsoids) and allows you to calculate geographical distances between coordinates with high precision.
Using Composer, just add it to your composer.json by running:
composer require mjaschen/phpgeo
Use the calculator object directly:
<?php
use Location\Coordinate;
use Location\Distance\Vincenty;
$coordinate1 = new Coordinate(19.820664, -155.468066); // Mauna Kea Summit
$coordinate2 = new Coordinate(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 Coordinate object by injecting a calculator object:
<?php
use Location\Coordinate;
use Location\Distance\Vincenty;
$coordinate1 = new Coordinate(19.820664, -155.468066); // Mauna Kea Summit
$coordinate2 = new Coordinate(20.709722, -156.253333); // Haleakala Summit
echo $coordinate1->getDistance($coordinate2, new Vincenty()); // returns 128130.850 (meters; ≈128 kilometers)There exist different methods for calculating the distance between two points. The Haversine formula is much faster the Vincenty's method but less precise:
<?php
use Location\Coordinate;
use Location\Distance\Haversine;
$coordinate1 = new Coordinate(19.820664, -155.468066); // Mauna Kea Summit
$coordinate2 = new Coordinate(20.709722, -156.253333); // Haleakala Summit
echo $coordinate1->getDistance($coordinate2, new Haversine()); // returns 128384.515 (meters; ≈128 kilometers)phpgeo has a polyline implementation which can be used to calculate the length of a GPS track or a route. A polyline consists of at least two points. Points are instances of the Coordinate class.
<?php
use Location\Coordinate;
use Location\Polyline;
use Location\Distance\Vincenty;
$track = new Polyline();
$track->addPoint(new Coordinate(52.5, 13.5));
$track->addPoint(new Coordinate(54.5, 12.5));
echo $track->getLength(new Vincenty());Polylines can be simplified to save storage space. Simplification is done with the Ramer–Douglas–Peucker algorithm (AKA Douglas-Peucker algorithm).
<?php
use Location\Coordinate;
use Location\Polyline;
use Location\Distance\Vincenty;
$polyline = new Polyline();
$polyline->addPoint(new Coordinate(10.0, 10.0));
$polyline->addPoint(new Coordinate(20.0, 20.0));
$polyline->addPoint(new Coordinate(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 Coordinate class.
<?php
$geofence = new Polygon();
$geofence->addPoint(new Coordinate(-12.085870,-77.016261));
$geofence->addPoint(new Coordinate(-12.086373,-77.033813));
$geofence->addPoint(new Coordinate(-12.102823,-77.030938));
$geofence->addPoint(new Coordinate(-12.098669,-77.006476));
$outsidePoint = new Coordinate(-12.075452, -76.985079);
$insidePoint = new Coordinate(-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 polygonYou can format a coordinate in different styles.
<?php
use Location\Coordinate;
use Location\Formatter\Coordinate\DecimalDegrees;
$coordinate = new Coordinate(19.820664, -155.468066); // Mauna Kea Summit
echo $coordinate->format(new DecimalDegrees());<?php
use Location\Coordinate;
use Location\Formatter\Coordinate\DMS;
$coordinate = new Coordinate(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\Coordinate;
use Location\Formatter\Coordinate\GeoJSON;
$coordinate = new Coordinate(18.911306, -155.678268); // South Point, HI, USA
echo $coordinate->format(new GeoJSON()); // { "type" : "point" , "coordinates" : [ -155.678268, 18.911306 ] }You can format a polyline in different styles.
<?php
use Location\Coordinate;
use Location\Polyline;
use Location\Formatter\Polyline\GeoJSON;
$polyline = new Polyline;
$polyline->addPoint(new Coordinate(52.5, 13.5));
$polyline->addPoint(new Coordinate(62.5, 14.5));
$formatter = new GeoJSON;
echo $formatter->format($polyline); // { "type" : "LineString" , "coordinates" : [ [ 13.5, 52.5 ], [ 14.5, 62.5 ] ] }- Marcus Jaschen mail@marcusjaschen.de
- 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.
- Richard Barnes Polyline GeoJSON Formatter