update examples to show streamplots

Author: murrayrm

examples/phase_plane_plots.py

@@ -15,6 +15,9 @@
 import control as ct
 import control.phaseplot as pp
 
+# Set default plotting parameters to match ControlPlot
+plt.rcParams.update(ct.rcParams)
+
 #
 # Example 1: Dampled oscillator systems
 #
@@ -32,17 +35,17 @@ def damposc_update(t, x, u, params):
 fig.set_tight_layout(True)
 plt.suptitle("FBS Figure 5.3: damped oscillator")
 
-ct.phase_plane_plot(damposc, [-1, 1, -1, 1], 8, ax=ax1, plot_streamlines=True)
+ct.phase_plane_plot(damposc, [-1, 1, -1, 1], 8, ax=ax1)
 ax1.set_title("boxgrid [-1, 1, -1, 1], 8")
 
 ct.phase_plane_plot(damposc, [-1, 1, -1, 1], ax=ax2, plot_streamlines=True,
                     gridtype='meshgrid')
-ax2.set_title("meshgrid [-1, 1, -1, 1]")
+ax2.set_title("streamlines, meshgrid [-1, 1, -1, 1]")
 
 ct.phase_plane_plot(
     damposc, [-1, 1, -1, 1], 4, ax=ax3, plot_streamlines=True,
     gridtype='circlegrid', dir='both')
-ax3.set_title("circlegrid [0, 0, 1], 4, both")
+ax3.set_title("streamlines, circlegrid [0, 0, 1], 4, both")
 
 ct.phase_plane_plot(
     damposc, [-1, 1, -1, 1], ax=ax4, gridtype='circlegrid',
@@ -65,18 +68,18 @@ def invpend_update(t, x, u, params):
 plt.suptitle("FBS Figure 5.4: inverted pendulum")
 
 ct.phase_plane_plot(
-    invpend, [-2*pi, 2*pi, -2, 2], 5, ax=ax1, plot_streamlines=True)
+    invpend, [-2*pi, 2*pi, -2, 2], 5, ax=ax1)
 ax1.set_title("default, 5")
 
 ct.phase_plane_plot(
     invpend, [-2*pi, 2*pi, -2, 2], gridtype='meshgrid', ax=ax2,
     plot_streamlines=True)
-ax2.set_title("meshgrid")
+ax2.set_title("streamlines, meshgrid")
 
 ct.phase_plane_plot(
     invpend, [-2*pi, 2*pi, -2, 2], 1, gridtype='meshgrid',
     gridspec=[12, 9], ax=ax3, arrows=1, plot_streamlines=True)
-ax3.set_title("denser grid")
+ax3.set_title("streamlines, denser grid")
 
 ct.phase_plane_plot(
     invpend, [-2*pi, 2*pi, -2, 2], 4, gridspec=[6, 6],
@@ -99,8 +102,7 @@ def oscillator_update(t, x, u, params):
 fig.set_tight_layout(True)
 plt.suptitle("FBS Figure 5.5: Nonlinear oscillator")
 
-ct.phase_plane_plot(oscillator, [-1.5, 1.5, -1.5, 1.5], 3, ax=ax1,
-                    plot_streamlines=True)
+ct.phase_plane_plot(oscillator, [-1.5, 1.5, -1.5, 1.5], 3, ax=ax1)
 ax1.set_title("default, 3")
 ax1.set_aspect('equal')
 
@@ -111,14 +113,14 @@ def oscillator_update(t, x, u, params):
 except RuntimeError as inst:
     ax2.text(0, 0, "Runtime Error")
     warnings.warn(inst.__str__())
-ax2.set_title("meshgrid, forward, 0.5")
+ax2.set_title("streamlines, meshgrid, forward, 0.5")
 ax2.set_aspect('equal')
 
 ct.phase_plane_plot(oscillator, [-1.5, 1.5, -1.5, 1.5], ax=ax3,
                     plot_streamlines=True)
 pp.streamlines(
     oscillator, [-0.5, 0.5, -0.5, 0.5], dir='both', ax=ax3)
-ax3.set_title("outer + inner")
+ax3.set_title("streamlines, outer + inner")
 ax3.set_aspect('equal')
 
 ct.phase_plane_plot(
@@ -143,12 +145,13 @@ def saddle_update(t, x, u, params):
 fig.set_tight_layout(True)
 plt.suptitle("FBS Figure 5.9: Saddle")
 
-ct.phase_plane_plot(saddle, [-1, 1, -1, 1], ax=ax1, plot_streamlines=True)
+ct.phase_plane_plot(saddle, [-1, 1, -1, 1], ax=ax1)
 ax1.set_title("default")
 
 ct.phase_plane_plot(
-    saddle, [-1, 1, -1, 1], 0.5, gridtype='meshgrid', ax=ax2, plot_streamlines=True)
-ax2.set_title("meshgrid")
+    saddle, [-1, 1, -1, 1], 0.5, plot_streamlines=True, gridtype='meshgrid',
+    ax=ax2)
+ax2.set_title("streamlines, meshgrid")
 
 ct.phase_plane_plot(
     saddle, [-1, 1, -1, 1], gridspec=[16, 12], ax=ax3, 
@@ -158,7 +161,7 @@ def saddle_update(t, x, u, params):
 ct.phase_plane_plot(
     saddle, [-1, 1, -1, 1], 0.3, plot_streamlines=True, 
     gridtype='meshgrid', gridspec=[5, 7], ax=ax4)
-ax3.set_title("custom")
+ax4.set_title("custom")
 
 #
 # Example 5: Internet congestion control
@@ -178,6 +181,7 @@ def _congctrl_update(t, x, u, params):
     return np.append(
         c / x[M] - (rho * c) * (1 + (x[:-1]**2) / 2),
         N/M * np.sum(x[:-1]) * c / x[M] - c)
+
 congctrl = ct.nlsys(
     _congctrl_update, states=2, inputs=0,
     params={'N': 60, 'rho': 2e-4, 'c': 10})
@@ -188,15 +192,15 @@ def _congctrl_update(t, x, u, params):
 
 try:
     ct.phase_plane_plot(
-        congctrl, [0, 10, 100, 500], 120, ax=ax1, plot_streamlines=True)
+        congctrl, [0, 10, 100, 500], 120, ax=ax1)
 except RuntimeError as inst:
     ax1.text(5, 250, "Runtime Error")
     warnings.warn(inst.__str__())
 ax1.set_title("default, T=120")
 
 try:
     ct.phase_plane_plot(
-        congctrl, [0, 10, 100, 500], 120, plot_streamlines=True,
+        congctrl, [0, 10, 100, 500], 120,
         params={'rho': 4e-4, 'c': 20}, ax=ax2)
 except RuntimeError as inst:
     ax2.text(5, 250, "Runtime Error")