c9ex15.m

来自「连续与离散信号系统的Matlab仿真示例代码．」· M 代码 · 共 19 行

f = [0 0.2 0.22 0.5 0.52 1];            % Specify f vector
m = [1 1 0.4 0.4 0 0];                  % Specify amplitude response
n = 30;                                 % Define n
b = remez(n,f,m);                       % Compute impulse response
[h,w] = freqz(b,1,512);                 % Compute frequency response
amp = abs(h);                           % Compute amplitude response
subplot(2,1,1)                          % Designate first subplot
plot(f/2,m,w/(2*pi),amp,'--')      % Plot amplitude response
xlabel('Normalized Frequency - r')      % Label x-axis
ylabel('Amplitude')                     % Label y-axis
phase = angle(h);                       % Calculate phase
phase = unwrap(phase);                  % Unwrap phase
phasedeg = phase*180/pi;                % Express phase in degrees
subplot(2,1,2)                          % Designate second subplot
plot(w/(2*pi),phasedeg,'--')           % Plot phase response
xlabel('Normalized Frequency - r')      % Label x-axis
ylabel('Phase - degrees')               % Label y-axis