代码：

ws1 = 0.2*pi; wp1 = 0.35*pi; wp2 = 0.65*pi; ws2 = 0.8*pi;Rp = 1.0; As = 60;[delta1, delta2] = db2delta(Rp, As);f = [ws1, wp1, wp2, ws2]/pi; m = [0, 1, 0]; delta = [delta2, delta1, delta2];[N, f, m, weights] = firpmord(f, m, delta); Nh = firpm(N, f, m, weights);[db, mag, pha, grd, w] = freqz_m(h, [1]);delta_w = 2*pi/1000; ws1i = floor(ws1/delta_w)+1; wp1i = floor(wp1/delta_w)+1;ws2i = floor(ws2/delta_w)+1; wp2i = floor(wp2/delta_w)+1;Asd = -max(db(1:1:ws1i))N = N +  1h = firpm(N, f, m, weights);[db, mag, pha, grd, w] = freqz_m(h, [1]);Asd = -max(db(1:1:ws1i))N = N +  1h = firpm(N, f, m, weights);[db, mag, pha, grd, w] = freqz_m(h, [1]);[Hr, ww, a, L] = Hr_Type1(h);Asd = -max(db(1:1:ws1i))M = N + 1

　　运行结果：

     当Asd超过给定的60dB就停止。