public function get_range()
{
$ne = new lat_lng($this->north, $this->east);
$sw = new lat_lng($this->south, $this->west);
$dist = $sw->get_distance_to($ne);
return $dist * 5;
}
public function get_distance_to(lat_lng $other)
{
$x = $this->sin_lat() * $other->sin_lat() + $this->cos_lat() * $other->cos_lat() * cos($this->lng(true) - $other->lng(true));
if (!is_nan($acos = acos($x))) {
return $acos * 6371;
} else {
return 0;
}
}
private static function __convert(lat_lng $point, $source_ellipse, $target_ellipse, $transform)
{
$lat = $point->lat(true);
$lon = $point->lng(true);
$a = $source_ellipse['a'];
$b = $source_ellipse['b'];
$sinPhi = sin($lat);
$cosPhi = cos($lat);
$sinLambda = sin($lon);
$cosLambda = cos($lon);
$H = 0;
// for the moment
$eSq = ($a * $a - $b * $b) / ($a * $a);
$nu = $a / sqrt(1 - $eSq * $sinPhi * $sinPhi);
$x1 = ($nu + $H) * $cosPhi * $cosLambda;
$y1 = ($nu + $H) * $cosPhi * $sinLambda;
$z1 = ((1 - $eSq) * $nu + $H) * $sinPhi;
$tx = $transform['tx'];
$ty = $transform['ty'];
$tz = $transform['tz'];
$rx = deg2rad($transform['rx'] / 3600);
$ry = deg2rad($transform['ry'] / 3600);
$rz = deg2rad($transform['rz'] / 3600);
$s1 = $transform['s'] / 1000000 + 1;
// normalise ppm to (s+1)
$x2 = $tx + $x1 * $s1 - $y1 * $rz + $z1 * $ry;
$y2 = $ty + $x1 * $rz + $y1 * $s1 - $z1 * $rx;
$z2 = $tz - $x1 * $ry + $y1 * $rx + $z1 * $s1;
$a = $target_ellipse['a'];
$b = $target_ellipse['b'];
$precision = 1 / 3600000000000.0;
$eSq = ($a * $a - $b * $b) / ($a * $a);
$p = sqrt($x2 * $x2 + $y2 * $y2);
$phi = atan2($z2, $p * (1 - $eSq));
$phiP = 2 * M_PI;
$iterations = 0;
while (abs($phi - $phiP) > $precision && $iterations < 10000000) {
$nu = $a / sqrt(1 - $eSq * sin($phi) * sin($phi));
$phiP = $phi;
$phi = atan2($z2 + $eSq * $nu * sin($phi), $p);
$iterations++;
}
$lambda = atan2($y2, $x2);
$H = $p / cos($phi) - $nu;
return new lat_lng(rad2deg($phi), rad2deg($lambda), $H);
}
public function contains(lat_lng $lat_lng)
{
return $this->north_east->lat() > $lat_lng->lat() && $this->south_west->lat() < $lat_lng->lat() && $this->north_east->lng() > $lat_lng->lng() && $this->south_west->lng() < $lat_lng->lng();
}
