/**
* Get the speed between this point and another point in km/h.
*
* @param TrackPoint $trackPoint The other point.
* @return float
*/
public function speed(TrackPoint $trackPoint)
{
$start = $this->getDateTime();
$end = $trackPoint->getDateTime();
$dateDiff = $start->diff($end);
$secondsDifference = $dateDiff->days * 86400 + $dateDiff->h * 3600 + $dateDiff->i * 60 + $dateDiff->s;
if ($secondsDifference === 0) {
return 0;
}
if ($this->hasDistance() === true && $trackPoint->hasDistance()) {
$distance = abs($this->getDistance() - $trackPoint->getDistance());
} else {
$distance = $this->distance($trackPoint);
}
return $distance / $secondsDifference * 3.6;
}