public function getIntersectionPoint()
{
if (!$this->circleA || !$this->circleB || !$this->circleC) {
return false;
}
$vectorP1 = $this->getECRVector($this->circleA);
$vectorP2 = $this->getECRVector($this->circleB);
$vectorP3 = $this->getECRVector($this->circleC);
#from wikipedia: http://en.wikipedia.org/wiki/Trilateration
#transform to get circle 1 at origin
#transform to get circle 2 on x axis
// CALC EX
$l = $vectorP2->subtract($vectorP1);
$norm = new Vector(array_fill(0, 3, $l->length()));
$d = $norm;
$ex = $l->divide($norm);
// CALC i
$P3minusP1 = $vectorP3->subtract($vectorP1);
$i = $ex->dotProduct($P3minusP1);
// CALC EY
$iex = $ex->multiplyByScalar($i);
$P3P1iex = $P3minusP1->subtract($iex);
$l = $P3P1iex;
$norm = new Vector(array_fill(0, 3, $l->length()));
$ey = $P3P1iex->divide($norm);
// CALC EZ
$ez = $ex->crossProduct($ey);
// CALC D
$d = $d->getElement(0);
// CALC J
$j = $ey->dotProduct($P3minusP1);
#from wikipedia
#plug and chug using above values
$x = (pow($this->circleA->getRadius(), 2) - pow($this->circleB->getRadius(), 2) + pow($d, 2)) / (2 * $d);
$y = (pow($this->circleA->getRadius(), 2) - pow($this->circleC->getRadius(), 2) + pow($i, 2) + pow($j, 2)) / (2 * $j) - $i / $j * $x;
# only one case shown here
$z = sqrt(pow($this->circleA->getRadius(), 2) - pow($x, 2) - pow($y, 2));
#triPt is an array with ECEF x,y,z of trilateration point
$xex = $ex->multiplyByScalar($x);
$yey = $ey->multiplyByScalar($y);
$zez = $ez->multiplyByScalar($z);
// CALC $triPt = $P1vector + $xex + $yey + $zez;
$triPt = $vectorP1->add($xex)->add($yey)->add($zez);
$triPtX = $triPt->getElement(0);
$triPtY = $triPt->getElement(1);
$triPtZ = $triPt->getElement(2);
#convert back to lat/long from ECEF
#convert to degrees
$lat = rad2deg(asin($triPtZ / $this->earthRadius));
$lng = rad2deg(atan2($triPtY, $triPtX));
return compact('lat', 'lng');
}
public function testRadius()
{
$circle = new Circle();
$circle->setRadius(10);
$this->assertEquals(10, $circle->getRadius());
}
}
public function setSideLength($length)
{
$this->_sideLength = $length;
}
public function getArea()
{
return pow($this->_sideLength, 2);
}
}
$myCircle = new Circle();
$myCircle->setColor("red");
$myCircle->fill();
$myCircle->setRadius(4);
echo "<h2>My Circle</h2>";
echo "<p>My circle has a radius of " . $myCircle->getRadius() . ".</p>";
echo "<p>It is " . $myCircle->getColor() . " and it is " . ($myCircle->isFilled() ? "filled" : "hollow") . ".</p>";
echo "<p>The area of my circle is: " . $myCircle->getArea() . ".</p>";
$mySquare = new Square();
$mySquare->setColor("green");
$mySquare->makeHollow();
$mySquare->setSideLength(3);
echo "<h2>My Square</h2>";
echo "<p>My square has a side length of " . $mySquare->getSideLength() . ".</p>";
echo "<p>It is " . $mySquare->getColor() . " and it is " . ($mySquare->isFilled() ? "filled" : "hollow") . ".</p>";
echo "<p>The area of my square is: " . $mySquare->getArea() . ".</p>";
?>
</body>
</html>
/**
* Created by PhpStorm.
* User: ET
* Date: 7/2/2015
* Time: 3:34 PM
*/
function __autoload($class)
{
include_once $class . '.php';
}
$s = new Sphere(23);
$o = new Oval(23, 11);
$c = new Cylinder(22, 7);
$circle = new Circle(12);
echo '<p>Radius of the circle is: ' . $circle->getRadius() . '</p>';
echo '<p>Circumference of the Circle: ' . $circle->getCircumference() . '</p>';
echo '<p>Area of the Circle: ' . $circle->getArea() . '</p>';
echo '-------------------------------------------';
echo '<p>Height of the Cylinder: ' . $c->getHeight() . '</p>';
echo '<p>Radius of the Cylinder: ' . $c->getRadius() . '</p>';
echo '<p>Area of the Cylinder: ' . $c->getArea() . '</p>';
echo '-------------------------------------------';
echo '<p>Area of the Oval: ' . $o->getArea() . '</p>';
echo '<p>Length of Semi-Major Axis of the Oval: ' . $o->getRadius() . '</p>';
echo '<p>Length of Semi-Minor Axis of the Oval: ' . $o->getRadius2() . '</p>';
echo '-------------------------------------------';
echo '<p>Area of the Sphere: ' . $s->getArea() . '</p>';
echo '-------------------------------------------';
echo '<p>Total Circle related created: ' . Circle::getCounter() . '</p>';
unset($c, $s, $circle);
