// Quaternion calculation of error in each axis.  Uses more memory.
		float rpy_desired[3];
		float q_desired[4];
		float q_error[4];
		float local_error[3];

		// Essentially zero errors for anything in rate or none
		if(stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_ROLL] == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE)
			rpy_desired[0] = stabDesired.Roll;
		else
			rpy_desired[0] = attitudeActual.Roll;

		if(stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_PITCH] == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE)
			rpy_desired[1] = stabDesired.Pitch;
		else
			rpy_desired[1] = attitudeActual.Pitch;

		if(stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_YAW] == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE)
			rpy_desired[2] = stabDesired.Yaw;
		else
			rpy_desired[2] = attitudeActual.Yaw;

		RPY2Quaternion(rpy_desired, q_desired);
		quat_inverse(q_desired);
		quat_mult(q_desired, &attitudeActual.q1, q_error);
		quat_inverse(q_error);
		Quaternion2RPY(q_error, local_error);