<?php
class Vector {
	public $x;
	public $y;
	public $include;

	public function __construct($x,$y) {
		$this->x = $x;
		$this->y = $y;
	}

	public function DotProduct(Vector $v) {
		$dot = ($this->x * $v->x + $this->y * $v->y);
		return $dot;
	}

	public function Magnitude() {
		return sqrt($this->x*$this->x + $this->y*$this->y);
	}

	public function UnitVector() {
		if ($this->Magnitude() == 0) return new Vector(0,0);
		return new Vector($this->x / $this->Magnitude(), $this->y / $this->Magnitude());
	}
}
?>