@murrayrm suggested changes e.g change default_frequency_range to private

sawyerbfuller · sawyerbfuller · commit acaea54e259f · 2021-01-29T00:04:31.000-08:00
diff --git a/control/bdalg.py b/control/bdalg.py
@@ -54,7 +54,6 @@
 """
 
 import numpy as np
-from scipy.signal.ltisys import StateSpace
 from . import xferfcn as tf
 from . import statesp as ss
 from . import frdata as frd
@@ -175,7 +174,7 @@ def negate(sys):
     >>> sys2 = negate(sys1) # Same as sys2 = -sys1.
 
     """
-    return -sys;
+    return -sys
 
 #! TODO: expand to allow sys2 default to work in MIMO case?
 def feedback(sys1, sys2=1, sign=-1):
@@ -281,10 +280,7 @@ def append(*sys):
     >>> sys = append(sys1, sys2)
 
     """
-    if not isinstance(sys[0], StateSpace):
-        s1 = ss._convert_to_statespace(sys[0])
-    else:
-        s1 = sys[0]
+    s1 = ss._convert_to_statespace(sys[0])
     for s in sys[1:]:
         s1 = s1.append(s)
     return s1
diff --git a/control/freqplot.py b/control/freqplot.py
@@ -199,7 +199,7 @@ def bode_plot(syslist, omega=None,
         omega_was_given = False # used do decide whether to include nyq. freq
         if omega_limits is None:
             # Select a default range if none is provided
-            omega = default_frequency_range(syslist, Hz=Hz,
+            omega = _default_frequency_range(syslist, Hz=Hz,
                                             number_of_samples=omega_num)
         else:
             omega_limits = np.asarray(omega_limits)
@@ -591,16 +591,14 @@ def nyquist_plot(syslist, omega=None, plot=True, omega_limits=None,
     if omega is None:
         if omega_limits is None:
             # Select a default range if none is provided
-            omega = default_frequency_range(syslist, Hz=False,
+            omega = _default_frequency_range(syslist, Hz=False,
                                             number_of_samples=omega_num)
         else:
             omega_limits = np.asarray(omega_limits)
             if len(omega_limits) != 2:
                 raise ValueError("len(omega_limits) must be 2")
-            if omega_num:
-                num = omega_num
-            else:
-                num = config.defaults['freqplot.number_of_samples']
+            num = \
+                ct.config._get_param('freqplot','number_of_samples', omega_num)
             omega = np.logspace(np.log10(omega_limits[0]),
                                 np.log10(omega_limits[1]), num=num,
                                 endpoint=True)
@@ -717,7 +715,7 @@ def gangof4_plot(P, C, omega=None, **kwargs):
     # Select a default range if none is provided
     # TODO: This needs to be made more intelligent
     if omega is None:
-        omega = default_frequency_range((P, C, S))
+        omega = _default_frequency_range((P, C, S))
 
     # Set up the axes with labels so that multiple calls to
     # gangof4_plot will superimpose the data.  See details in bode_plot.
@@ -798,7 +796,7 @@ def gangof4_plot(P, C, omega=None, **kwargs):
 #
 
 # Compute reasonable defaults for axes
-def default_frequency_range(syslist, Hz=None, number_of_samples=None,
+def _default_frequency_range(syslist, Hz=None, number_of_samples=None,
                             feature_periphery_decades=None):
     """Compute a reasonable default frequency range for frequency
     domain plots.
@@ -832,7 +830,7 @@ def default_frequency_range(syslist, Hz=None, number_of_samples=None,
     --------
     >>> from matlab import ss
     >>> sys = ss("1. -2; 3. -4", "5.; 7", "6. 8", "9.")
-    >>> omega = default_frequency_range(sys)
+    >>> omega = _default_frequency_range(sys)
 
     """
     # This code looks at the poles and zeros of all of the systems that
diff --git a/control/nichols.py b/control/nichols.py
@@ -52,7 +52,7 @@
 import numpy as np
 import matplotlib.pyplot as plt
 from .ctrlutil import unwrap
-from .freqplot import default_frequency_range
+from .freqplot import _default_frequency_range
 from . import config
 
 __all__ = ['nichols_plot', 'nichols', 'nichols_grid']
@@ -91,7 +91,7 @@ def nichols_plot(sys_list, omega=None, grid=None):
 
     # Select a default range if none is provided
     if omega is None:
-        omega = default_frequency_range(sys_list)
+        omega = _default_frequency_range(sys_list)
 
     for sys in sys_list:
         # Get the magnitude and phase of the system
