求大神帮忙 啊 求讲解这个matlab程序的每一句的意思啊哦哦 closeall;clearall; clc t = -2:0.0001:2; omega = 2 * pi; y = square(2 * pi * t,50); n_max = [1 3 5 9 19 39 79 159]; N = length(n_max); for k = 1:N fk = zeros(1,length(t)); for n = 1:2:n_max(k) bn = 4 / (pi * n); fk = fk + bn * sin(n * omega * t); end figure;plot(t,y,t,fk,'Linewidth',2); xlabel('t(sec)');ylabel('部分和的波形'); -2 -1.5-1-0.5 00.511.52 -3 -2 -1 0 1 2 3 f(t) t(sec) String = ['最大谐波数=',num2str(n_max(k))]; axis([-2 2 -3 3]);grid;title(String); disp([String,'时，在信号跳变点附近的过冲幅度（%）']); f_max = (max(fk) - max(y)) / (max(y) - min(y)) * 100 end