Added display of GM and PM in bode plot. Fixed Hz bug support. Fixed phase limit bug.

icam0 · icam0 · commit bde60f58833e · 2018-05-28T15:06:27.000+02:00
diff --git a/control/freqplot.py b/control/freqplot.py
@@ -86,7 +86,7 @@ def bode_plot(syslist, omega=None, dB=None, Hz=None, deg=None,
     omega_num: int
         number of samples
     margins : boolean
-        if True, plot gain and phase margin
+        If True, plot gain and phase margin
     *args, **kwargs:
         Additional options to matplotlib (color, linestyle, etc)
 
@@ -233,10 +233,14 @@ def bode_plot(syslist, omega=None, dB=None, Hz=None, deg=None,
                 if margins:
                     margin = stability_margins(sys)
                     gm, pm, Wcg, Wcp = margin[0], margin[1], margin[3], margin[4]
-                    if pm >= 0.:
-                        phase_limit = -180.
-                    else:
+                    phase_at_cp = phases[0][(np.abs(omegas[0] - Wcp)).argmin()]
+                    if phase_at_cp >= 0.:
                         phase_limit = 180.
+                    else:
+                        phase_limit = -180.
+
+                    if Hz:
+                        Wcg, Wcp = Wcg/(2*math.pi),Wcp/(2*math.pi)
 
                     ax_mag.axhline(y=0 if dB else 1, color='k', linestyle=':')
                     ax_phase.axhline(y=phase_limit if deg else math.radians(phase_limit), color='k', linestyle=':')
@@ -271,7 +275,14 @@ def bode_plot(syslist, omega=None, dB=None, Hz=None, deg=None,
 
                     ax_mag.set_ylim(mag_ylim)
                     ax_phase.set_ylim(phase_ylim)
-                    plt.suptitle('Gm = %.2f %s(at %.2f rad/s), Pm = %.2f %s (at %.2f rad/s)'%(20*np.log10(gm) if dB else gm,'dB ' if dB else '\b',Wcg,pm if deg else math.radians(pm),'deg' if deg else 'rad',Wcp))
+
+                    if sisotool:
+                        ax_mag.text(0.04, 0.06, 'G.M.: %.2f %s\nFreq: %.2f %s'%(20*np.log10(gm) if dB else gm,'dB ' if dB else '\b',Wcg,'Hz' if Hz else 'rad/s'), horizontalalignment='left', verticalalignment='bottom',
+                                    transform=ax_mag.transAxes,fontsize=10)
+                        ax_phase.text(0.04, 0.06, 'P.M.: %.2f %s\nFreq: %.2f %s'%(pm if deg else math.radians(pm),'deg' if deg else 'rad',Wcp,'Hz' if Hz else 'rad/s'), horizontalalignment='left', verticalalignment='bottom',
+                                    transform=ax_phase.transAxes,fontsize=10)
+                    else:
+                        plt.suptitle('Gm = %.2f %s(at %.2f %s), Pm = %.2f %s (at %.2f %s)'%(20*np.log10(gm) if dB else gm,'dB ' if dB else '\b','Hz' if Hz else 'rad/s',Wcg,pm if deg else math.radians(pm),'deg' if deg else 'rad',Wcp,'Hz' if Hz else 'rad/s'))
 
                 if nyquistfrq_plot:
                     ax_phase.axvline(nyquistfrq_plot, color=pltline[0].get_color())
@@ -644,6 +655,11 @@ def gen_prefix(pow1000):
             'z',  # zepto (10^-21)
             'y'][8 - pow1000]  # yocto (10^-24)
 
+def find_nearest_omega(omega_list, omega):
+    omega_list = np.asarray(omega_list)
+    idx = (np.abs(omega_list - omega)).argmin()
+    return omega_list[(np.abs(omega_list - omega)).argmin()]
+
 # Function aliases
 bode = bode_plot
 nyquist = nyquist_plot
diff --git a/control/rlocus.py b/control/rlocus.py
@@ -382,7 +382,6 @@ def _RLFeedbackClicksPoint(event,sys,fig,ax_rlocus=None,sisotool=False):
     (nump, denp) = _systopoly1d(sys)
     s = complex(event.xdata, event.ydata)
     K = -1. / sys.horner(s)
-    print(K)
     if abs(K.real) > 1e-8 and abs(K.imag / K.real) < 0.04 and event.inaxes == ax_rlocus.axes:
 
         # Display the parameters in the output window and figure
diff --git a/control/sisotool.py b/control/sisotool.py
@@ -5,7 +5,7 @@
 from .lti import issiso
 import matplotlib.pyplot as plt
 
-def sisotool(sys, kvect = None, xlim = None, ylim = None, plotstr_rlocus = '-',rlocus_grid = False, omega = None, dB = None, Hz = None, deg = None, omega_limits = None, omega_num = None, tvect=None):
+def sisotool(sys, kvect = None, xlim = None, ylim = None, plotstr_rlocus = '-',rlocus_grid = False, omega = None, dB = None, Hz = None, deg = None, omega_limits = None, omega_num = None,margins = True, tvect=None):
 
     from .rlocus import root_locus
 
@@ -29,6 +29,7 @@ def sisotool(sys, kvect = None, xlim = None, ylim = None, plotstr_rlocus = '-',r
         'omega_num' : omega_num,
         'sisotool': True,
         'fig': fig,
+        'margins': margins,
     }
 
     # First time call to setup the bode and step response plots
