removed bug where a pole or zero would be deleted if only 1 of them was present

icam0 · icam0 · commit 94a0ea154a7c · 2018-05-30T13:04:06.000+02:00
diff --git a/control/rlocus.py b/control/rlocus.py
@@ -131,7 +131,7 @@ def root_locus(sys, kvect=None, xlim=None, ylim=None, plotstr='-', Plot=True,
                 'button_release_event', partial(_RLFeedbackClicksPoint,sys=sys,fig=f))
 
         elif sisotool == True:
-            f.axes[1].plot([root.real for root in start_mat], [root.imag for root in start_mat], 'm.', marker='s', markersize=8,zorder=20)
+            f.axes[1].plot([root.real for root in start_mat], [root.imag for root in start_mat], 'm.', marker='s', markersize=8,zorder=20,label='gain_point')
             f.suptitle("Clicked at: %10.4g%+10.4gj  gain: %10.4g  damp: %10.4g" % (start_mat[0][0].real, start_mat[0][0].imag, 1, -1 * start_mat[0][0].real / abs(start_mat[0][0])),fontsize = 12 if int(matplotlib.__version__[0]) == 1 else 10)
             f.canvas.mpl_connect(
                 'button_release_event',partial(_RLFeedbackClicksSisotool,sys=sys, fig=f, bode_plot_params=kwargs['bode_plot_params'],tvect=kwargs['tvect']))
@@ -380,7 +380,6 @@ def _RLFeedbackClicksSisotool(event,sys,fig,bode_plot_params,tvect):
 def _RLFeedbackClicksPoint(event,sys,fig,ax_rlocus=None,sisotool=False):
     """Display root-locus gain feedback point for clicks on the root-locus plot
     """
-    print(event)
     if sisotool == False:
         ax_rlocus = fig.axes[0]
 
@@ -397,17 +396,17 @@ def _RLFeedbackClicksPoint(event,sys,fig,ax_rlocus=None,sisotool=False):
 
         # Remove the previous points
         for line in reversed(ax_rlocus.lines):
-            if len(line.get_xdata()) == 1:
+            if len(line.get_xdata()) == 1 and line.get_label()=='gain_point':
                 line.remove()
                 del line
 
         # Visualise clicked point, display all roots for sisotool mode
         if sisotool:
             mymat = _RLFindRoots(nump, denp, K.real)
             ax_rlocus.plot([root.real for root in mymat], [root.imag for root in mymat], 'm.', marker='s', markersize=8,
-                           zorder=20)
+                           zorder=20,label='gain_point')
         else:
-            ax_rlocus.plot(s.real, s.imag, 'k.', marker='s', markersize=8, zorder=20)
+            ax_rlocus.plot(s.real, s.imag, 'k.', marker='s', markersize=8, zorder=20,label='gain_point')
 
         # Update the canvas
         fig.canvas.draw()
diff --git a/control/tests/sisotool_test.py b/control/tests/sisotool_test.py
@@ -10,15 +10,11 @@ class TestSisotool(unittest.TestCase):
     """These are tests for the sisotool in sisotool.py."""
 
     def setUp(self):
-        """This contains some random LTI systems and scalars for testing."""
-
-        # Two random SISO systems.
-        sys1 = TransferFunction([1000],[1,25,100,0])
-        sys2 = TransferFunction([1,1,1],[1,1])
-        self.systems = (sys1, sys2)
+        # One random SISO system.
+        self.system = TransferFunction([1000],[1,25,100,0])
 
     def test_sisotool(self):
-        sisotool(self.systems[0])
+        sisotool(self.system)
         fig = plt.gcf()
         ax_mag,ax_rlocus,ax_phase,ax_step = fig.axes[0],fig.axes[1],fig.axes[2],fig.axes[3]
 
@@ -53,7 +49,7 @@ def test_sisotool(self):
 
         # Move the rootlocus to another point
         event = type('test', (object,), {'xdata': 2.31206868287,'ydata':15.5983051046, 'inaxes':ax_rlocus.axes})()
-        _RLFeedbackClicksSisotool(event=event, sys=self.systems[0], fig=fig, bode_plot_params=bode_plot_params, tvect=None)
+        _RLFeedbackClicksSisotool(event=event, sys=self.system, fig=fig, bode_plot_params=bode_plot_params, tvect=None)
 
         # Check the moved root locus plot points
         moved_point_0 = (np.array([-29.91742755]), np.array([0.]))
