[python-control-discuss] SF.net python-control commit:[247] trunk

[<mur...@us...>]

Revision: 247
          http://sourceforge.net/p/python-control/code/247
Author:   murrayrm
Date:     2012-11-19 05:28:05 +0000 (Mon, 19 Nov 2012)
Log Message:
-----------
Set up 'config' module that allows user-defined defaults

 * Will eventually allow MATLAB defaults if user imports control.matlab first

New module 'canonical' for implementing canconical forms.  Needed for
trajectory generation module (coming soon).

Modified Paths:
--------------
    trunk/ChangeLog
    trunk/src/__init__.py
    trunk/src/freqplot.py
    trunk/src/matlab.py
    trunk/src/statesp.py
    trunk/src/xferfcn.py

Added Paths:
-----------
    trunk/src/canonical.py
    trunk/src/config.py

Property Changed:
----------------
    trunk/
    trunk/src/
    trunk/tests/


Property changes on: trunk
___________________________________________________________________
Modified: svn:ignore
   - MANIFEST*
build
dist

   + MANIFEST*
build
dist
__pycache__


Modified: trunk/ChangeLog
===================================================================
--- trunk/ChangeLog	2012-11-11 22:00:29 UTC (rev 246)
+++ trunk/ChangeLog	2012-11-19 05:28:05 UTC (rev 247)
@@ -1,3 +1,31 @@
+2012-11-10  Richard Murray  <murray@altura.local>
+
+	* src/canonical.py: new module implementing conversions to selected
+	canonical forms: canonical_form(), reachable_form() implemented
+
+	* src/lti.py (issiso): new function to quickly check if a system is
+	single input, single output or not
+
+2012-11-04  Richard Murray  <murray@altura.local>
+
+	* src/__init__.py: added action item to separate out matlab module
+	functionality (eventually)
+
+	* src/matlab.py: added code for setting up MATLAB defaults if matlab
+	submodule is imported instead of main (control) module.  See
+	comments in __init.py__ for what needs to be done to implement.
+
+	* src/freqplot.py (bode_plot): moved default values of plotting
+	options to config module to allow easier use override
+
+	* src/config.py: new module to help set package defaults
+
+	* src/xferfcn.py (_convertToTransferFunction): removed extraneous
+	print statements if slycot is not installed
+
+	* src/statesp.py (StateSpace.__str__): fixed error in printing
+	timebase when dt is None (python 3)
+
 ---- control-0.6c released -----
 
 2012-11-03  Richard Murray  <murray@altura.local>


Property changes on: trunk/src
___________________________________________________________________
Modified: svn:ignore
   - *.pyc
.*.swp

   + *.pyc
.*.swp
__pycache__


Modified: trunk/src/__init__.py
===================================================================
--- trunk/src/__init__.py	2012-11-11 22:00:29 UTC (rev 246)
+++ trunk/src/__init__.py	2012-11-19 05:28:05 UTC (rev 247)
@@ -63,7 +63,7 @@
 from control.dtime import sample_system
 from control.freqplot import bode_plot, nyquist_plot, gangof4_plot
 from control.freqplot import bode, nyquist, gangof4
-from control.lti import timebase, timebaseEqual, isdtime, isctime
+from control.lti import issiso, timebase, timebaseEqual, isdtime, isctime
 from control.margins import stability_margins, phase_crossover_frequencies
 from control.mateqn import lyap, dlyap, care, dare
 from control.modelsimp import hsvd, modred, balred, era, markov
@@ -77,9 +77,20 @@
 from control.xferfcn import TransferFunction
 from control.ctrlutil import unwrap, issys
 from control.frdata import FRD
+from control.canonical import canonical_form, reachable_form
 
+# Exceptions
+from exception import *
+
 # Import some of the more common (and benign) MATLAB shortcuts
 # By default, don't import conflicting commands here
+#! TODO (RMM, 4 Nov 2012): remove MATLAB dependencies from __init__.py
+#!
+#! Eventually, all functionality should be in modules *other* than matlab.
+#! This will allow inclusion of the matlab module to set up a different set
+#! of defaults from the main package.  At that point, the matlab module will
+#! allow provide compatibility with MATLAB but no package functionality.
+#!
 from control.matlab import ss, tf, ss2tf, tf2ss, drss
 from control.matlab import pole, zero, evalfr, freqresp, dcgain
 from control.matlab import nichols, rlocus, margin

Added: trunk/src/canonical.py
===================================================================
--- trunk/src/canonical.py	                        (rev 0)
+++ trunk/src/canonical.py	2012-11-19 05:28:05 UTC (rev 247)
@@ -0,0 +1,64 @@
+# canonical.py - functions for converting systems to canonical forms
+# RMM, 10 Nov 2012
+
+import control
+from numpy import zeros, shape, poly
+from numpy.linalg import inv
+
+def canonical_form(sys, form):
+    """Convert a system into canonical form
+
+    Parameters
+    ----------
+    xsys : StateSpace object
+        System to be transformed, with state 'x'
+    form : String
+        Canonical form for transformation.  Chosen from:
+          * 'reachable' - reachable canonical form
+          * 'observable' - observable canonical form
+          * 'modal' - modal canonical form [not implemented]
+
+    Outputs
+    -------
+    zsys : StateSpace object
+        System in desired canonical form, with state 'z'
+    T : matrix
+        Coordinate transformation matrix, z = T*x
+    """
+
+    # Call the appropriate tranformation function
+    if form == 'reachable':
+        return reachable_form(xsys)
+    else:
+        raise control.ControlNotImplemented(
+            "Canonical form '%s' not yet implemented" % form)
+
+# Reachable canonical form
+def reachable_form(xsys):
+    # Check to make sure we have a SISO system
+    if not control.issiso(xsys): 
+        raise control.ControlNotImplemented(
+            "Canonical forms for MIMO systems not yet supported")
+
+    # Create a new system, starting with a copy of the old one
+    zsys = control.StateSpace(xsys)
+
+    # Generate the system matrices for the desired canonical form
+    zsys.B = zeros(shape(xsys.B)); zsys.B[0, 0] = 1;
+    zsys.A = zeros(shape(xsys.A))
+    Apoly = poly(xsys.A)                # characteristic polynomial
+    for i in range(0, xsys.states):
+        zsys.A[0, i] = -Apoly[i+1] / Apoly[0]
+        if (i+1 < xsys.states): zsys.A[i+1, i] = 1
+    
+    # Compute the reachability matrices for each set of states
+    Wrx = control.ctrb(xsys.A, xsys.B)
+    Wrz = control.ctrb(zsys.A, zsys.B)
+
+    # Transformation from one form to another
+    Tzx = Wrz * inv(Wrx)
+
+    # Finally, compute the output matrix
+    zsys.C = xsys.C * inv(Tzx)
+
+    return zsys, Tzx

Added: trunk/src/config.py
===================================================================
--- trunk/src/config.py	                        (rev 0)
+++ trunk/src/config.py	2012-11-19 05:28:05 UTC (rev 247)
@@ -0,0 +1,27 @@
+# config.py - package defaults
+# RMM, 4 Nov 2012
+#
+# This file contains default values and utility functions for setting
+# variables that control the behavior of the control package.
+# Eventually it will be possible to read and write configuration
+# files.  For now, you can just choose between MATLAB and FBS default
+# values.
+
+# Bode plot defaults
+bode_dB = False                 # Bode plot magnitude units
+bode_deg = True                 # Bode Plot phase units
+bode_Hz = False                 # Bode plot frequency units
+
+# Set defaults to match MATLAB
+def use_matlab_defaults():
+    # Bode plot defaults
+    global bode_dB; bode_dB = True
+    global bode_deg; bode_deg = True
+    global bode_Hz; bode_Hz = True
+
+# Set defaults to match FBS (Astrom and Murray)
+def use_fbs_defaults():
+    # Bode plot defaults
+    global bode_dB; bode_dB = False
+    global bode_deg; bode_deg = True
+    global bode_Hz; bode_Hz = True

Modified: trunk/src/freqplot.py
===================================================================
--- trunk/src/freqplot.py	2012-11-11 22:00:29 UTC (rev 246)
+++ trunk/src/freqplot.py	2012-11-19 05:28:05 UTC (rev 247)
@@ -57,7 +57,7 @@
 #
    
 # Bode plot
-def bode_plot(syslist, omega=None, dB=False, Hz=False, deg=True, 
+def bode_plot(syslist, omega=None, dB=None, Hz=None, deg=None, 
         Plot=True, *args, **kwargs):
     """Bode plot for a system
 
@@ -105,6 +105,12 @@
     >>> sys = ss("1. -2; 3. -4", "5.; 7", "6. 8", "9.")
     >>> mag, phase, omega = bode(sys)
     """
+    # Set default values for options
+    import control.config
+    if (dB is None): dB = control.config.bode_dB
+    if (deg is None): deg = control.config.bode_deg
+    if (Hz is None): Hz = control.config.bode_Hz
+
     # If argument was a singleton, turn it into a list
     if (not getattr(syslist, '__iter__', False)):
         syslist = (syslist,)

Modified: trunk/src/matlab.py
===================================================================
--- trunk/src/matlab.py	2012-11-11 22:00:29 UTC (rev 246)
+++ trunk/src/matlab.py	2012-11-19 05:28:05 UTC (rev 247)
@@ -69,6 +69,18 @@
 from scipy.signal import zpk2ss, ss2zpk, tf2zpk, zpk2tf
 from numpy import linspace, logspace
 
+# If configuration is not yet set, import and use MATLAB defaults
+#! NOTE (RMM, 4 Nov 2012): MATLAB default initialization commented out for now
+#!
+#! This code will eventually be used so that import control.matlab will
+#! automatically use MATLAB defaults, while import control will use package
+#! defaults.  In order for that to work, we need to make sure that
+#! __init__.py does not include anything in the MATLAB module.  
+# import sys
+# if not ('control.config' in sys.modules):
+#     import control.config
+#    control.config.use_matlab()
+
 # Control system library
 import control.ctrlutil as ctrlutil
 import control.freqplot as freqplot

Modified: trunk/src/statesp.py
===================================================================
--- trunk/src/statesp.py	2012-11-11 22:00:29 UTC (rev 246)
+++ trunk/src/statesp.py	2012-11-19 05:28:05 UTC (rev 247)
@@ -138,6 +138,7 @@
 
         # Here we're going to convert inputs to matrices, if the user gave a
         # non-matrix type.
+        #! TODO: [A, B, C, D] = map(matrix, [A, B, C, D])?
         matrices = [A, B, C, D] 
         for i in range(len(matrices)):
             # Convert to matrix first, if necessary.
@@ -215,9 +216,10 @@
         str += "B = " + self.B.__str__() + "\n\n"
         str += "C = " + self.C.__str__() + "\n\n"
         str += "D = " + self.D.__str__() + "\n"
+        #! TODO: replace with standard calls to lti functions
         if (type(self.dt) == bool and self.dt == True):
             str += "\ndt unspecified\n"
-        elif (self.dt > 0):
+        elif (not (self.dt is None) and type(self.dt) != bool and self.dt > 0):
             str += "\ndt = " + self.dt.__str__() + "\n"
         return str
 

Modified: trunk/src/xferfcn.py
===================================================================
--- trunk/src/xferfcn.py	2012-11-11 22:00:29 UTC (rev 246)
+++ trunk/src/xferfcn.py	2012-11-19 05:28:05 UTC (rev 247)
@@ -266,6 +266,7 @@
         
         mimo = self.inputs > 1 or self.outputs > 1  
         if (var == None):
+            #! TODO: replace with standard calls to lti functions
             var = 's' if self.dt == None or self.dt == 0 else 'z'
         outstr = ""
         
@@ -294,6 +295,7 @@
 
         # See if this is a discrete time system with specific sampling time
         if (not (self.dt is None) and type(self.dt) != bool and self.dt > 0):
+            #! TODO: replace with standard calls to lti functions
             outstr += "\ndt = " + self.dt.__str__() + "\n"
 
         return outstr
@@ -945,8 +947,8 @@
             lti_sys = lti(sys.A, sys.B, sys.C, sys.D)
             num = squeeze(lti_sys.num)
             den = squeeze(lti_sys.den)
-            print(num)
-            print(den)
+            # print(num)
+            # print(den)
 
         return TransferFunction(num, den, sys.dt)
 


Property changes on: trunk/tests
___________________________________________________________________
Added: svn:ignore
   + __pycache__