代码:
%% ------------------------------------------------------------------------ %% Output Info about this m-file fprintf(‘\n***********************************************************\n‘); fprintf(‘ <DSP using MATLAB> Exameple 8.6 \n\n‘); time_stamp = datestr(now, 31); [wkd1, wkd2] = weekday(today, ‘long‘); fprintf(‘ Now is %20s, and it is %9s \n‘, time_stamp, wkd2); %% ------------------------------------------------------------------------ Wp = 0.2*pi; Ws = 0.3*pi; Rp = 1; As =16; Ripple = 10 ^ (-Rp/20); Attn = 10 ^ (-As/20); % Analog filter design: [b, a] = afd_chb1(Wp, Ws, Rp, As); % Calculation of second-order sections: [C, B, A] = sdir2cas(b, a) % Calculation of Frequency Response: [db, mag, pha, ww] = freqs_m(b, a, 0.5*pi); % Calculation of Impulse Response: [ha, x, t] = impulse(b, a); %% ------------------------------------------------- %% Plot %% ------------------------------------------------- figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘Exameple 8.6‘) set(gcf,‘Color‘,‘white‘); M = 0.5; % Omega max subplot(2,2,1); plot(ww/pi, mag); axis([0, M, 0, 1.2]); grid on; xlabel(‘ Analog frequency in \pi units‘); ylabel(‘|H|‘); title(‘Magnitude Response‘); set(gca, ‘XTickMode‘, ‘manual‘, ‘XTick‘, [0, 0.2, 0.3, M]); set(gca, ‘YTickMode‘, ‘manual‘, ‘YTick‘, [0, 0.1585, 0.8913, 1]); subplot(2,2,2); plot(ww/pi, db); axis([0, M, -30, 10]); grid on; xlabel(‘Analog frequency in \pi units‘); ylabel(‘Decibels‘); title(‘Magnitude in dB ‘); set(gca, ‘XTickMode‘, ‘manual‘, ‘XTick‘, [0, 0.2, 0.3, M]); set(gca, ‘YTickMode‘, ‘manual‘, ‘YTick‘, [-30, -16, -1, 0]); subplot(2,2,3); plot(ww/pi, pha/pi); axis([0, M, -1.1, 1.1]); grid on; xlabel(‘Analog frequency in \pi nuits‘); ylabel(‘radians in \pi units‘); title(‘Phase Response‘); set(gca, ‘XTickMode‘, ‘manual‘, ‘XTick‘, [0, 0.2, 0.3, M]); set(gca, ‘YTickMode‘, ‘manual‘, ‘YTick‘, [-1:0.5:1]); subplot(2,2,4); plot(t, ha); axis([0, 50, -0.1, 0.25]); grid on; xlabel(‘time in seconds‘); ylabel(‘ha(t)‘); title(‘Impulse Response‘);
运行结果:
时间: 2024-11-07 17:48:27