www.gusucode.com > robust 案例源码程序 matlab代码 > robust/PlotMultipleFrequencyResponsesExample.m
%% Plot Multiple Frequency Responses % Create two SISO second-order systems, and calculate their frequency responses % over different frequency ranges. %% % Copyright 2015 The MathWorks, Inc. a1 = [-1,1;-1,-0.5]; b1 = [0;2]; c1 = [1,0]; d1 = 0; sys1 = ss(a1,b1,c1,d1); a2 = [-.1,1;-1,-0.05]; b2 = [1;1]; c2 = [-0.5,0]; d2 = 0.1; sys2 = ss(a2,b2,c2,d2); omega = logspace(-2,2,100); sys1g = frd(sys1,omega); omega2 = [ [0.05:0.1:1.5] [1.6:.5:20] [0.9:0.01:1.1] ]; omega2 = sort(omega2); sys2g = frd(sys2,omega2); %% % Create an |frd| object with a single frequency. sys3 = rss(1,1,1); rspot = frd(sys3,2); %% % The following plot uses the |plot_type| specification |'liv,lm'|. uplot('liv,lm',sys1g,'b-.',rspot,'r*-',sys2g); xlabel('log independent variable') ylabel('log magnitude') title('axis specification: liv,lm') %%