说明：  包括用窗函数法和最大误差最小化准则设计的FIR低通数字滤波器，并分析加矩形窗时的吉布斯现象（matlab程序）。从仿真结果可看出：采用最大误差最小化准则能得到阶数更低，阻带波纹特性更好的FIR低通滤波器，因此其效果更优。
(Including the use of window function method and the maximum error criterion designed to minimize the FIR low-pass digital filter, and analyze the increase of the Gibbs phenomenon when the rectangular window (matlab procedure). From the simulation results can be seen: The maximum error is minimum order of the criteria to get a lower stop-band ripple characteristics of a better FIR low-pass filter, so the results better.)