1 files changed, 23 insertions, 0 deletions
diff --git a/257/CH11/EX11.18/example_11_18.sce b/257/CH11/EX11.18/example_11_18.sce
new file mode 100644
index 000000000..e53d295b6
--- /dev/null
+++ b/257/CH11/EX11.18/example_11_18.sce
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+s=poly(0,'s'); 
+F=syslin('c',[4/((1+s)^3)]) 
+
+fmin=0.1;                                 //Min freq in Hz
+fmax=20;                                  //Max freq in Hz
+scf(1);clf;
+bode(F,fmin,fmax);                        //Plots frequency response of open-loop system in Bode diagram
+
+[GainMargin,freqGM]=g_margin(F)           //Calculates gain margin [dB] and corresponding frequency [Hz]
+disp(GainMargin,"GM=")
+disp(freqGM*2*3.14,"omegaPC=")
+
+[PhaseMargin,freqPM]=p_margin(F)               //Calculates phase [deg] and corresponding freq [Hz] of phase margin
+disp(PhaseMargin,"PM=")
+disp(freqPM*2*3.14,"omegaGC")
+
+show_margins(F)                                   //display gain and phase margin and associated crossover frequencies
+
+if(GainMargin>0 & PhaseMargin>0 )
+    disp("stable system")
+else
+    disp("unstable system")
+end