Added a copy() deepcopy routine to Lti subclasses.

Kevin Chen · Kevin Chen · commit f9fed5ac45c4 · 2011-02-08T22:17:51.000Z
Also renamed rss_generate to _rss_generate and corrected some comments.

Kevin K. Chen &lt;kkchen@princeton.edu&gt;
diff --git a/src/bdalg.py b/src/bdalg.py
@@ -9,7 +9,9 @@
 negate
 feedback
 
-Copyright (c) 2010 by California Institute of Technology
+"""
+
+"""Copyright (c) 2010 by California Institute of Technology
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/src/lti.py b/src/lti.py
@@ -21,6 +21,7 @@ class Lti:
     "virtual" functions.  These are:
 
     __init__
+    copy
     __str__
     __neg__
     __add__
diff --git a/src/matlab.py b/src/matlab.py
@@ -13,7 +13,9 @@
 have the same names as their MATLAB equivalents are automatically
 imported here.
 
-Copyright (c) 2009 by California Institute of Technology
+"""
+
+"""Copyright (c) 2009 by California Institute of Technology
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -65,7 +67,7 @@
 # Control system library
 import ctrlutil
 import freqplot
-from statesp import StateSpace, rss_generate, convertToStateSpace
+from statesp import StateSpace, _rss_generate, convertToStateSpace
 from xferfcn import TransferFunction, convertToTransferFunction
 from exception import ControlArgument
 
@@ -511,7 +513,7 @@ def rss(states=1, inputs=1, outputs=1):
      
     """
     
-    return rss_generate(states, inputs, outputs, 'c')
+    return _rss_generate(states, inputs, outputs, 'c')
     
 def drss(states=1, inputs=1, outputs=1):
     """
@@ -544,7 +546,7 @@ def drss(states=1, inputs=1, outputs=1):
      
     """
     
-    return rss_generate(states, inputs, outputs, 'd')
+    return _rss_generate(states, inputs, outputs, 'd')
     
 def pole(sys):
     """
diff --git a/src/statesp.py b/src/statesp.py
@@ -9,6 +9,8 @@
 Routines in this module:
 
 StateSpace.__init__
+StateSpace._remove_useless_states
+StateSpace.copy
 StateSpace.__str__
 StateSpace.__neg__
 StateSpace.__add__
@@ -26,9 +28,11 @@
 StateSpace.feedback
 StateSpace.returnScipySignalLti
 convertToStateSpace
-rss_generate
+_rss_generate
 
-Copyright (c) 2010 by California Institute of Technology
+"""
+
+"""Copyright (c) 2010 by California Institute of Technology
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -74,6 +78,7 @@
 from numpy.linalg import inv, det, solve
 from numpy.linalg.linalg import LinAlgError
 from scipy.signal import lti
+from copy import deepcopy
 from slycot import td04ad
 from lti import Lti
 import xferfcn
@@ -162,6 +167,11 @@ def _remove_useless_states(self):
             self.B = delete(self.B, useless, 0)
             self.C = delete(self.C, useless, 1)
 
+    def copy(self):
+        """Return a deep copy of the instance."""
+
+        return deepcopy(self)
+
     def __str__(self):
         """String representation of the state space."""
 
@@ -207,9 +217,9 @@ def __add__(self, other):
 
         return StateSpace(A, B, C, D)
 
-    # Reverse addition - just switch the arguments
+    # Right addition - just switch the arguments
     def __radd__(self, other): 
-        """Reverse add two LTI systems (parallel connection)."""
+        """Right add two LTI systems (parallel connection)."""
         
         return self + other
 
@@ -220,7 +230,7 @@ def __sub__(self, other):
         return self + (-other)
 
     def __rsub__(self, other):
-        """Reverse subtract two LTI systems."""
+        """Right subtract two LTI systems."""
 
         return other + (-self)
 
@@ -253,10 +263,10 @@ def __mul__(self, other):
 
         return StateSpace(A, B, C, D)
 
-    # Reverse multiplication of two transfer functions (series interconnection)
+    # Right multiplication of two transfer functions (series interconnection)
     # Just need to convert LH argument to a state space object
     def __rmul__(self, other):
-        """Reverse multiply two LTI objects (serial connection)."""
+        """Right multiply two LTI objects (serial connection)."""
         
         # Check for a couple of special cases
         if isinstance(other, (int, long, float, complex)):
@@ -276,7 +286,7 @@ def __div__(self, other):
         raise NotImplementedError("StateSpace.__div__ is not implemented yet.")
 
     def __rdiv__(self, other):
-        """Reverse divide two LTI systems."""
+        """Right divide two LTI systems."""
 
         raise NotImplementedError("StateSpace.__rdiv__ is not implemented yet.")
 
@@ -465,7 +475,7 @@ def convertToStateSpace(sys, **kw):
     else:
         raise TypeError("Can't convert given type to StateSpace system.")
     
-def rss_generate(states, inputs, outputs, type):
+def _rss_generate(states, inputs, outputs, type):
     """Generate a random state space.
     
     This does the actual random state space generation expected from rss and
diff --git a/src/xferfcn.py b/src/xferfcn.py
@@ -10,6 +10,7 @@
 
 TransferFunction.__init__
 TransferFunction._truncatecoeff
+TransferFunction.copy
 TransferFunction.__str__
 TransferFunction.__neg__
 TransferFunction.__add__
@@ -31,7 +32,9 @@
 _addSISO
 convertToTransferFunction
 
-Copyright (c) 2010 by California Institute of Technology
+"""
+
+"""Copyright (c) 2010 by California Institute of Technology
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -208,6 +211,11 @@ def _truncatecoeff(self):
                         data[p][i][j] = data[p][i][j][nonzero:]        
         [self.num, self.den] = data
     
+    def copy(self):
+        """Return a deep copy of the instance."""
+
+        return deepcopy(self)
+
     def __str__(self):
         """String representation of the transfer function."""
         
@@ -276,7 +284,7 @@ def __add__(self, other):
         return TransferFunction(num, den)
  
     def __radd__(self, other): 
-        """Reverse add two LTI objects (parallel connection)."""
+        """Right add two LTI objects (parallel connection)."""
         
         return self + other;
         
@@ -286,7 +294,7 @@ def __sub__(self, other):
         return self + (-other)
         
     def __rsub__(self, other): 
-        """Reverse subtract two LTI objects."""
+        """Right subtract two LTI objects."""
         
         return other + (-self)
 
@@ -328,7 +336,7 @@ def __mul__(self, other):
         return TransferFunction(num, den)
 
     def __rmul__(self, other): 
-        """Reverse multiply two LTI objects (serial connection)."""
+        """Right multiply two LTI objects (serial connection)."""
         
         return self * other
 
@@ -351,7 +359,7 @@ def __div__(self, other):
        
     # TODO: Division of MIMO transfer function objects is not written yet.
     def __rdiv__(self, other):
-        """Reverse divide two LTI objects."""
+        """Right divide two LTI objects."""
         
         if (self.inputs > 1 or self.outputs > 1 or 
             other.inputs > 1 or other.outputs > 1):
