starting GPS clustering algorithm implementation

Author: bdelespierre

src/Gps/Algorithm.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Kmeans\Gps;
+
+use Kmeans\Algorithm as BaseAlgorithm;
+use Kmeans\Interfaces\PointCollectionInterface;
+use Kmeans\Interfaces\PointInterface;
+use Kmeans\Math;
+
+class Algorithm extends BaseAlgorithm
+{
+    protected function getDistanceBetween(PointInterface $pointA, PointInterface $pointB): float
+    {
+        if (! $pointA instanceof Point || ! $pointB instanceof Point) {
+            throw new \InvalidArgumentException(
+                "Expecting \\Kmeans\\GPS\\Point"
+            );
+        }
+
+        return Math::haversine($pointA->getCoordinates(), $pointB->getCoordinates());
+    }
+
+    protected function findCentroid(PointCollectionInterface $points): PointInterface
+    {
+        if (! $points->getSpace() instanceof Space) {
+            throw new \InvalidArgumentException(
+                "Point collection should consist of GPS coordinates"
+            );
+        }
+
+        /** @var array<Point> $points */
+        $points = iterator_to_array($points);
+
+        return new Point(Math::gpsCentroid(
+            array_map(fn (Point $point) => $point->getCoordinates(), $points)
+        ));
+    }
+}

src/Gps/Point.php

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+<?php
+
+namespace Kmeans\Gps;
+
+use Kmeans\Point as BasePoint;
+
+/**
+ * @method array{0: float, 1: float} getCoordinates()
+ */
+class Point extends BasePoint
+{
+    /**
+     * @param array<float> $coordinates
+     */
+    public function __construct(array $coordinates)
+    {
+        $this->validateCoordinates($coordinates);
+
+        parent::__construct(new Space(), $coordinates);
+    }
+
+    /**
+     * @param array<float> $coordinates
+     */
+    private function validateCoordinates(array $coordinates): void
+    {
+        if (count($coordinates) != 2) {
+            throw new \InvalidArgumentException(
+                "Invalid GPS coordinates"
+            );
+        }
+
+        list($lat, $long) = $coordinates;
+
+        if ($lat < -90 || $lat > 90 || $long < -180 || $long > 180) {
+            throw new \InvalidArgumentException(
+                "Invalid GPS coordinates"
+            );
+        }
+    }
+}

src/Gps/Space.php

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+<?php
+
+namespace Kmeans\Gps;
+
+use Kmeans\Space as BaseSpace;
+
+class Space extends BaseSpace
+{
+    public function __construct()
+    {
+        parent::__construct(2);
+    }
+}