/**
* Calculate the distance between two
* points using the Great Circle formula.
*
* Supply instances of the coordinate class.
*
* http://www.ga.gov.au/earth-monitoring/geodesy/geodetic-techniques/distance-calculation-algorithms.html#circle
*
* @param Treffynnon\Navigator\Coordinate $point1
* @param Treffynnon\Navigator\Coordinate $point2
* @return float
*/
public function calculate(N\LatLong $point1, N\LatLong $point2)
{
$celestialBody = $this->getCelestialBody();
$degrees = acos(sin($point1->getLatitude()->get()) * sin($point2->getLatitude()->get()) + cos($point1->getLatitude()->get()) * cos($point2->getLatitude()->get()) * cos($point2->getLongitude()->get() - $point1->getLongitude()->get()));
$d = $degrees * $celestialBody->volumetricMeanRadius;
return $d * 1000;
}
public function testPrimeCoordinateParsers()
{
$latitude = new N\Coordinate(10.03);
$longitude = new N\Coordinate('10 10 1.2S', new C\DmsParser());
$LatLong = new N\LatLong($latitude, $longitude);
$this->assertEquals($LatLong->getLongitude()->getParser()->getDirection(), T\Navigator::Long);
$this->assertEquals($LatLong->getLatitude()->getParser()->getDirection(), T\Navigator::Lat);
}
/**
* Calculate the distance between two
* points using the Haversine formula.
*
* Supply instances of the coordinate class.
*
* http://en.wikipedia.org/wiki/Haversine_formula
*
* @param Treffynnon\Navigator\Coordinate $point1
* @param Treffynnon\Navigator\Coordinate $point2
* @return float
*/
public function calculate(N\LatLong $point1, N\LatLong $point2)
{
$celestialBody = $this->getCelestialBody();
$deltaLat = $point2->getLatitude()->get() - $point1->getLatitude()->get();
$deltaLong = $point2->getLongitude()->get() - $point1->getLongitude()->get();
$a = sin($deltaLat / 2) * sin($deltaLat / 2) + cos($point1->getLatitude()->get()) * cos($point2->getLatitude()->get()) * sin($deltaLong / 2) * sin($deltaLong / 2);
$c = 2 * atan2(sqrt($a), sqrt(1 - $a));
$d = $celestialBody->volumetricMeanRadius * $c * 1000;
return $d;
}
/**
* Calculate the distance between two
* points using Vincenty's formula.
*
* Supply instances of the coordinate class.
*
* http://www.movable-type.co.uk/scripts/LatLongVincenty.html
*
* @param Treffynnon\Navigator\Coordinate $point1
* @param Treffynnon\Navigator\Coordinate $point2
* @return float
*/
public function calculate(N\LatLong $point1, N\LatLong $point2)
{
$celestialBody = $this->getCelestialBody();
$a = $celestialBody->equatorialRadius;
$b = $celestialBody->polarRadius;
$f = $celestialBody->flattening;
//flattening of the ellipsoid
$L = $point2->getLongitude()->get() - $point1->getLongitude()->get();
//difference in longitude
$U1 = atan((1 - $f) * tan($point1->getLatitude()->get()));
//U is 'reduced latitude'
$U2 = atan((1 - $f) * tan($point2->getLatitude()->get()));
$sinU1 = sin($U1);
$sinU2 = sin($U2);
$cosU1 = cos($U1);
$cosU2 = cos($U2);
$lambda = $L;
$lambdaP = 2 * pi();
$i = 20;
while (abs($lambda - $lambdaP) > 1.0E-12 && --$i > 0) {
$sinLambda = sin($lambda);
$cosLambda = cos($lambda);
$sinSigma = sqrt($cosU2 * $sinLambda * ($cosU2 * $sinLambda) + ($cosU1 * $sinU2 - $sinU1 * $cosU2 * $cosLambda) * ($cosU1 * $sinU2 - $sinU1 * $cosU2 * $cosLambda));
if ($sinSigma == 0) {
return 0;
}
//co-incident points
$cosSigma = $sinU1 * $sinU2 + $cosU1 * $cosU2 * $cosLambda;
$sigma = atan2($sinSigma, $cosSigma);
$sinAlpha = $cosU1 * $cosU2 * $sinLambda / $sinSigma;
$cosSqAlpha = 1 - $sinAlpha * $sinAlpha;
$cos2SigmaM = $cosSigma - 2 * $sinU1 * $sinU2 / $cosSqAlpha;
if (is_nan($cos2SigmaM)) {
$cos2SigmaM = 0;
}
//equatorial line: cosSqAlpha=0 (6)
$c = $f / 16 * $cosSqAlpha * (4 + $f * (4 - 3 * $cosSqAlpha));
$lambdaP = $lambda;
$lambda = $L + (1 - $c) * $f * $sinAlpha * ($sigma + $c * $sinSigma * ($cos2SigmaM + $c * $cosSigma * (-1 + 2 * $cos2SigmaM * $cos2SigmaM)));
}
if ($i == 0) {
return false;
}
//formula failed to converge
$uSq = $cosSqAlpha * ($a * $a - $b * $b) / ($b * $b);
$A = 1 + $uSq / 16384 * (4096 + $uSq * (-768 + $uSq * (320 - 175 * $uSq)));
$B = $uSq / 1024 * (256 + $uSq * (-128 + $uSq * (74 - 47 * $uSq)));
$deltaSigma = $B * $sinSigma * ($cos2SigmaM + $B / 4 * ($cosSigma * (-1 + 2 * $cos2SigmaM * $cos2SigmaM) - $B / 6 * $cos2SigmaM * (-3 + 4 * $sinSigma * $sinSigma) * (-3 + 4 * $cos2SigmaM * $cos2SigmaM)));
$d = $b * $A * ($sigma - $deltaSigma);
return $d;
}
public function testFromString()
{
$latitude = '42.77';
$longitude = '-2.86844';
$LatLong = N\LatLong::createFromString($latitude . ',' . $longitude);
$this->assertInstanceOf('Treffynnon\\Navigator\\LatLong', $LatLong);
$this->assertEquals($latitude, (string) $LatLong->getLatitude());
$this->assertEquals($longitude, (string) $LatLong->getLongitude());
}