python-control · murrayrm · Jan 27, 2021 · Jan 24, 2021 · Jan 24, 2021 · Jan 24, 2021
diff --git a/control/tests/convert_test.py b/control/tests/convert_test.py
@@ -155,7 +155,7 @@ def testConvert(self, fixedseed, states, inputs, outputs):
     def testConvertMIMO(self):
         """Test state space to transfer function conversion.
 
-        Do a MIMO conversation and make sure that it is processed
+        Do a MIMO conversion and make sure that it is processed
         correctly both with and without slycot
 
         Example from issue gh-120, jgoppert

diff --git a/control/timeresp.py b/control/timeresp.py
@@ -356,7 +356,7 @@ def forced_response(sys, T=None, U=0., X0=0., transpose=False,
     if isinstance(sys, TransferFunction) and np.any(X0 != 0):
         warnings.warn(
             "Non-zero initial condition given for transfer function system. "
-            "Internal conversation to state space used; may not be consistent "
+            "Internal conversion to state space used; may not be consistent "
             "with given X0.")
 
     xout = np.zeros((n_states, n_steps))
@@ -702,7 +702,7 @@ def step_response(sys, T=None, X0=0., input=None, output=None, T_num=None,
     if isinstance(sys, TransferFunction) and np.any(X0 != 0):
         warnings.warn(
             "Non-zero initial condition given for transfer function system. "
-            "Internal conversation to state space used; may not be consistent "
+            "Internal conversion to state space used; may not be consistent "
             "with given X0.")
 
     # Convert to state space so that we can simulate

diff --git a/examples/robust_mimo.py b/examples/robust_mimo.py
@@ -54,11 +54,8 @@ def analysis():
     g = plant()
 
     t = np.linspace(0, 10, 101)
-    _, yu1 = step_response(g, t, input=0)
-    _, yu2 = step_response(g, t, input=1)
-
-    yu1 = yu1
-    yu2 = yu2
+    _, yu1 = step_response(g, t, input=0, squeeze=True)
+    _, yu2 = step_response(g, t, input=1, squeeze=True)
 
     # linear system, so scale and sum previous results to get the
     # [1,-1] response
@@ -112,8 +109,8 @@ def synth(wb1, wb2):
 
 def step_opposite(g, t):
     """reponse to step of [-1,1]"""
-    _, yu1 = step_response(g, t, input=0)
-    _, yu2 = step_response(g, t, input=1)
+    _, yu1 = step_response(g, t, input=0, squeeze=True)
+    _, yu2 = step_response(g, t, input=1, squeeze=True)
     return yu1 - yu2
 
 

diff --git a/examples/secord-matlab.py b/examples/secord-matlab.py
@@ -24,7 +24,7 @@
 
 # Bode plot for the system
 plt.figure(2)
-mag, phase, om = bode(sys, logspace(-2, 2), Plot=True)
+mag, phase, om = bode(sys, logspace(-2, 2), plot=True)
 plt.show(block=False)
 
 # Nyquist plot for the system

diff --git a/examples/test-response.py b/examples/test-response.py
@@ -4,7 +4,9 @@
 import os
 import matplotlib.pyplot as plt  # MATLAB plotting functions
 from control.matlab import *    # Load the controls systems library
-from scipy import arange        # function to create range of numbers
+from numpy import arange        # function to create range of numbers
+
+from control import reachable_form
 
 # Create several systems for testing
 sys1 = tf([1], [1, 2, 1])
@@ -13,10 +15,18 @@
 # Generate step responses
 (y1a, T1a) = step(sys1)
 (y1b, T1b) = step(sys1, T=arange(0, 10, 0.1))
-(y1c, T1c) = step(sys1, X0=[1, 0])
+# convert to reachable canonical SS to specify initial state
+sys1_ss = reachable_form(ss(sys1))[0]
+(y1c, T1c) = step(sys1_ss, X0=[1, 0])
 (y2a, T2a) = step(sys2, T=arange(0, 10, 0.1))
 
-plt.plot(T1a, y1a, T1b, y1b, T1c, y1c, T2a, y2a)
+plt.plot(T1a, y1a, label='$g_1$ (default)', linewidth=5)
+plt.plot(T1b, y1b, label='$g_1$ (w/ spec. times)', linestyle='--')
+plt.plot(T1c, y1c, label='$g_1$ (w/ init cond.)')
+plt.plot(T2a, y2a, label='$g_2$ (w/ spec. times)')
+plt.xlabel('time')
+plt.ylabel('output')
+plt.legend()
 
 if 'PYCONTROL_TEST_EXAMPLES' not in os.environ:
-    plt.show()
+    plt.show()