double angle_to_radian(double degree, double min, double second)
{
	double flag = (degree < 0) ? -1.0 : 1.0;
	if (degree < 0)
	{
		degree = degree * (-1.0);
	}
	double angle = degree + min / 60 + second / 3600;
	double result = flag * (angle * PI) / 180;
	return result;
}

这里提供一个PI的近似值：3.1415926535897932364626