实现跟踪光源的程序包，当光源位置变化时，可以自动改变位置误差，最终使误差为0-Implementation package tracking light, when the light source position changes, can automatically change the position error, the error is finally 0

. The normalized least mean square is the most popular due to its simplicity. The stability of the basic NLMS is controlled by a fixed step size. This parameter also governs the rate of convergence, speed of tracking ability and the amount of steady-