public final void yaw(double angle) {
		if (ZAXIS_ANGLE == -angle) {
			ZAXIS_ANGLE = angle;
			ZAXIS_TURN.entry[0][1] = -ZAXIS_TURN.entry[0][1];
			ZAXIS_TURN.entry[1][0] = -ZAXIS_TURN.entry[1][0];
		} else if (ZAXIS_ANGLE != angle) {
			// Cache it!
			ZAXIS_ANGLE = angle;
			angle = Math.toRadians(angle);
			double c = Math.cos(angle), s = Math.sin(angle);
			ZAXIS_TURN = new Matrix(c, -s, 0.0, 0.0, s, c, 0.0, 0.0, 0.0, 0.0,
					1.0, 0.0);
		}
		premultiply(ZAXIS_TURN);
	}