public JJVector minus(JJVector v, JJVector result)
{
result.set(mX - v.x(), mY - v.y(), mT - v.t());
return(result);
}
public JJVector plus(JJVector v, JJVector result)
{
result.set(mX + v.x(), mY + v.y(), mT + v.t());
return(result);
}