Re: [python-control-discuss] Fwd: SF.net SVN: python-control:[21] trunk

[Tony V. <ton...@al...>]

Doesn't look like I received it. I also checked my spam folder just in  
case.

-tv


On Jun 6, 2010, at 10:31, Richard Murray <mu...@cd...> wrote:

> Tony and Erik:
>
> Can you let me know if you got the note below from SourceForge.  I  
> just posted some changes to the package (needed them for an example  
> I'm putting together) and want to make sure that everyone is getting  
> copies of the changes that got posted.  If not, I'll sort out what  
> we need to change to make sure you get these sorts of e-mails.
>
> Thanks.
>
> -richard
>
> Begin forwarded message:
>
>> From: mur...@us...
>> Date: 6 June 2010 10:29:43 PDT
>> To: mu...@cd...
>> Subject: SF.net SVN: python-control:[21] trunk
>>
>> Revision: 21
>>         http://python-control.svn.sourceforge.net/python-control/?rev=21&view=rev
>> Author:   murrayrm
>> Date:     2010-06-06 17:29:42 +0000 (Sun, 06 Jun 2010)
>>
>> Log Message:
>> -----------
>> Added changes to allow bode() to plot frequency resp for multiple  
>> systems
>> * freqplot.bode now allows a list as the first argument
>> * Added matlab.bode wrapper for MATLAB syntax: bode(sys1, ..., sysN)
>>
>> Added automatic frequency range determination in bode
>> * Computes range of frequencies based on pole/zero locations
>> * Eventually need to split this out as a ctrlutil function for use  
>> elsewhere
>>
>> Modified Paths:
>> --------------
>>   trunk/ChangeLog
>>   trunk/src/ctrlutil.py
>>   trunk/src/freqplot.py
>>   trunk/src/matlab.py
>>   trunk/src/pzmap.py
>>   trunk/src/statesp.py
>>   trunk/src/xferfcn.py
>>
>> Modified: trunk/ChangeLog
>> ===================================================================
>> --- trunk/ChangeLog    2010-06-01 02:08:20 UTC (rev 20)
>> +++ trunk/ChangeLog    2010-06-06 17:29:42 UTC (rev 21)
>> @@ -1,3 +1,25 @@
>> +2010-06-06  Richard Murray  <murray@sumatra.local>
>> +
>> +    * src/matlab.py (bode): created a wrapper that allows MATLAB  
>> style
>> +    arguments for bode (eg, bode(sys1, sys2))
>> +
>> +    * src/ctrlutil.py (issys): added new function to check if an  
>> object
>> +    is a system (state space or transfer function).  Will generalize
>> +    this latter to look for other compatible classes.
>> +
>> +    * src/freqplot.py (bode): Compute frequency range of bode plot  
>> based
>> +    on poles and zeros
>> +    (bode): Allow bode plot to be passed a list (or tuple) as the  
>> first
>> +    argument, in which case multiple bode plots are generated
>> +
>> +    * src/statesp.py (StateSpace.zeros): new function to compute  
>> zeros
>> +    for a state space system
>> +    (StateSpace): defined new functions to compute poles of a state
>> +    space system
>> +
>> +    * src/xferfcn.py (TransferFunction): defined new functions to
>> +    compute poles and zeros of a transfer function.
>> +
>> 2010-05-31  Richard Murray  <murray@sumatra.local>
>>
>>    * src/exception.py (ControlNotImplemented): added new exception,  
>> to
>>
>> Modified: trunk/src/ctrlutil.py
>> ===================================================================
>> --- trunk/src/ctrlutil.py    2010-06-01 02:08:20 UTC (rev 20)
>> +++ trunk/src/ctrlutil.py    2010-06-06 17:29:42 UTC (rev 21)
>> @@ -40,6 +40,12 @@
>> #
>> # $Id$
>>
>> +# Packages that we need access to
>> +import scipy as sp
>> +import statesp
>> +import xferfcn
>> +
>> +# Specific functions that we use
>> from scipy import pi
>>
>> # Utility function to unwrap an angle measurement
>> @@ -78,3 +84,12 @@
>>
>>    # return the updated list
>>    return angle
>> +
>> +# Determine if an object is a system
>> +def issys(object):
>> +    # Check for a member of one of the classes that we define here
>> +    if (isinstance(object, (statesp.StateSpace,  
>> xferfcn.TransferFunction))):
>> +        return True
>> +
>> +    # Didn't find anything that matched
>> +    return False
>>
>> Modified: trunk/src/freqplot.py
>> ===================================================================
>> --- trunk/src/freqplot.py    2010-06-01 02:08:20 UTC (rev 20)
>> +++ trunk/src/freqplot.py    2010-06-06 17:29:42 UTC (rev 21)
>> @@ -42,11 +42,12 @@
>>
>> import matplotlib.pyplot as plt
>> import scipy as sp
>> +import numpy as np
>> from ctrlutil import unwrap
>> from bdalg import feedback
>>
>> # Bode plot
>> -def bode(sys, omega=None, dB=False, Hz=False):
>> +def bode(syslist, omega=None, dB=False, Hz=False):
>>    """Bode plot for a system
>>
>>    Usage
>> @@ -57,8 +58,8 @@
>>
>>    Parameters
>>    ----------
>> -    sys : linsys
>> -        Linear input/output system
>> +    syslist : linsys
>> +        List of linear input/output systems (single system is OK)
>>    omega : freq_range
>>        Range of frequencies (list or bounds) in rad/sec
>>    dB : boolean
>> @@ -76,45 +77,80 @@
>>    1. Use (mag, phase, freq) = sys.freqresp(freq) to generate the
>>       frequency response for a system.
>>    """
>> +    # If argument was a singleton, turn it into a list
>> +    if (not getattr(syslist, '__iter__', False)):
>> +        syslist = (syslist,)
>> +
>> +    #
>>    # Select a default range if none is provided
>> +    #
>> +    # This code looks at the poles and zeros of all of the systems  
>> that
>> +    # we are plotting and sets the frequency range to be one  
>> decade above
>> +    # and below the min and max feature frequencies, rounded to  
>> the nearest
>> +    # integer.  It excludes poles and zeros at the origin.  If no  
>> features
>> +    # are found, it turns logspace(-1, 1)
>> +    #
>>    if (omega == None):
>> -        omega = sp.logspace(-2, 2);
>> +        # Find the list of all poles and zeros in the systems
>> +        features = np.array(())
>> +        for sys in syslist:
>> +            # Add new features to the list
>> +            features = np.concatenate((features, np.abs(sys.poles)))
>> +            features = np.concatenate((features, np.abs(sys.zeros)))
>>
>> -    # Get the magnitude and phase of the system
>> -    mag, phase, omega = sys.freqresp(omega)
>> -    if Hz:
>> -        omega = omega/(2*sp.pi)
>> -    if dB:
>> -        mag = 20*sp.log10(mag)
>> -    phase = unwrap(phase*180/sp.pi, 360)
>> +        # Get rid of poles and zeros at the origin
>> +        features = features[features != 0];
>>
>> -    # Get the dimensions of the current axis, which we will divide  
>> up
>> -    #! TODO: Not current implemented; just use subplot for now
>> +        # Make sure there is at least one point in the range
>> +        if (features.shape[0] == 0): features = [1];
>>
>> -    # Magnitude plot
>> -    plt.subplot(211);
>> -    if dB:
>> -        plt.semilogx(omega, mag)
>> -    else:
>> -        plt.loglog(omega, mag)
>> -    plt.grid(True)
>> -    plt.grid(True, which='minor')
>> -    if dB:
>> -        plt.ylabel("Magnitude (dB)")
>> -    else:
>> -        plt.ylabel("Magnitude")
>> +        # Take the log of the features
>> +        features = np.log10(features)
>>
>> -    # Phase plot
>> -    plt.subplot(212);
>> -    plt.semilogx(omega, phase)
>> -    plt.grid(True)
>> -    plt.grid(True, which='minor')
>> -    plt.ylabel("Phase (deg)")
>> -    if Hz:
>> -        plt.xlabel("Frequency (Hz)")
>> -    else:
>> -        plt.xlabel("Frequency (rad/sec)")
>> +        # Set the to be an order of magnitude beyond any features
>> +        omega = sp.logspace(np.floor(np.min(features))-1,
>> +                            np.ceil(np.max(features))+1)
>>
>> +    for sys in syslist:
>> +        # Get the magnitude and phase of the system
>> +        mag, phase, omega = sys.freqresp(omega)
>> +        if Hz: omega = omega/(2*sp.pi)
>> +        if dB: mag = 20*sp.log10(mag)
>> +        phase = unwrap(phase*180/sp.pi, 360)
>> +
>> +        # Get the dimensions of the current axis, which we will  
>> divide up
>> +        #! TODO: Not current implemented; just use subplot for now
>> +
>> +        # Magnitude plot
>> +        plt.subplot(211);
>> +        if dB:
>> +            plt.semilogx(omega, mag)
>> +            plt.ylabel("Magnitude (dB)")
>> +        else:
>> +            plt.loglog(omega, mag)
>> +            plt.ylabel("Magnitude")
>> +
>> +        # Add a grid to the plot
>> +        plt.grid(True)
>> +        plt.grid(True, which='minor')
>> +        plt.hold(True);
>> +
>> +        # Phase plot
>> +        plt.subplot(212);
>> +        plt.semilogx(omega, phase)
>> +        plt.hold(True)
>> +
>> +        # Add a grid to the plot
>> +        plt.grid(True)
>> +        plt.grid(True, which='minor')
>> +        plt.ylabel("Phase (deg)")
>> +
>> +        # Label the frequency axis
>> +        if Hz:
>> +            plt.xlabel("Frequency (Hz)")
>> +        else:
>> +            plt.xlabel("Frequency (rad/sec)")
>> +
>>    return (211, 212)
>>
>> # Nyquist plot
>>
>> Modified: trunk/src/matlab.py
>> ===================================================================
>> --- trunk/src/matlab.py    2010-06-01 02:08:20 UTC (rev 20)
>> +++ trunk/src/matlab.py    2010-06-06 17:29:42 UTC (rev 21)
>> @@ -50,6 +50,7 @@
>>
>> # Libraries that we make use of
>> import scipy as sp              # SciPy library (used all over)
>> +import numpy as np              # NumPy library
>> import scipy.signal as signal   # Signal processing library
>>
>> # Import MATLAB-like functions that are defined in other packages
>> @@ -57,11 +58,16 @@
>> from scipy.signal import lsim, impulse, step
>> from scipy import linspace, logspace
>>
>> -# Import MATLAB-like functions that belong elsewhere in python- 
>> control
>> -from ctrlutil import unwrap
>> -from freqplot import bode, nyquist, gangof4
>> +# Control system library
>> +import ctrlutil
>> +import freqplot
>> from statesp import StateSpace
>> from xferfcn import TransferFunction
>> +from exception import *
>> +
>> +# Import MATLAB-like functions that can be used as-is
>> +from ctrlutil import unwrap
>> +from freqplot import nyquist, gangof4
>> from bdalg import series, parallel, negate, feedback
>> from pzmap import pzmap
>> from statefbk import place, lqr
>> @@ -304,3 +310,63 @@
>> def freqresp(H, omega):
>>    """Return the frequency response for an object H at frequency  
>> omega"""
>>    return H.freqresp(omega)
>> +
>> +# Bode plots
>> +def bode(*args, **keywords):
>> +    """Bode plot of the frequency response
>> +
>> +    Usage
>> +    =====
>> +    bode(sys)
>> +    bode(sys, w)
>> +    bode(sys1, sys2, ..., sysN)
>> +    bode(sys1, sys2, ..., sysN, w)
>> +    bode(sys1, 'plotstyle1', ..., sysN, 'plotstyleN')
>> +    """
>> +
>> +    # If the first argument is a list, then assume python-control  
>> calling format
>> +    if (getattr(args[0], '__iter__', False)):
>> +        return freqplot.bode(*args, **keywords)
>> +
>> +    # Otherwise, run through the arguments and collect up arguments
>> +    syslist = []; plotstyle=[]; omega=None;
>> +    i = 0;
>> +    while i < len(args):
>> +        # Check to see if this is a system of some sort
>> +        if (ctrlutil.issys(args[i])):
>> +            # Append the system to our list of systems
>> +            syslist.append(args[i])
>> +            i += 1
>> +
>> +            # See if the next object is a plotsytle (string)
>> +            if (i < len(args) and isinstance(args[i], str)):
>> +                plotstyle.append(args[i])
>> +                i += 1
>> +
>> +            # Go on to the next argument
>> +            continue
>> +
>> +        # See if this is a frequency list
>> +        elif (isinstance(args[i], (list, np.ndarray))):
>> +            omega = args[i]
>> +            i += 1
>> +            break
>> +
>> +        else:
>> +            raise ControlArgument("unrecognized argument type")
>> +
>> +    # Check to make sure that we processed all arguments
>> +    if (i < len(args)):
>> +        raise ControlArgument("not all arguments processed")
>> +
>> +    # Check to make sure we got the same number of plotstyles as  
>> systems
>> +    if (len(plotstyle) != 0 and len(syslist) != len(plotstyle)):
>> +        raise ControlArgument("number of systems and plotstyles  
>> should be equal")
>> +
>> +    # Warn about unimplemented plotstyles
>> +    #! TODO: remove this when plot styles are implemented in bode()
>> +    if (len(plotstyle) != 0):
>> +        print("Warning (matabl.bode): plot styles not implemented");
>> +
>> +    # Call the bode command
>> +    return freqplot.bode(syslist, omega, **keywords)
>>
>> Modified: trunk/src/pzmap.py
>> ===================================================================
>> --- trunk/src/pzmap.py    2010-06-01 02:08:20 UTC (rev 20)
>> +++ trunk/src/pzmap.py    2010-06-06 17:29:42 UTC (rev 21)
>> @@ -45,6 +45,7 @@
>> import xferfcn
>>
>> # Compute poles and zeros for a system
>> +#! TODO: extend this to handle state space systems
>> def pzmap(sys, Plot=True):
>>    """Plot a pole/zero map for a transfer function"""
>>    if (isinstance(sys, xferfcn.TransferFunction)):
>>
>> Modified: trunk/src/statesp.py
>> ===================================================================
>> --- trunk/src/statesp.py    2010-06-01 02:08:20 UTC (rev 20)
>> +++ trunk/src/statesp.py    2010-06-06 17:29:42 UTC (rev 21)
>> @@ -98,6 +98,18 @@
>>        #! TODO: Not implemented
>>        return None
>>
>> +    # Compute poles and zeros
>> +    def poles(self): return sp.roots(sp.poly(self.A))
>> +    def zeros(self):
>> +        den = sp.poly1d(sp.poly(self.A))
>> +
>> +        # Compute the numerator based on zeros
>> +        #! TODO: This is currently limited to SISO systems
>> +        num = sp.poly1d(\
>> +            sp.poly(self.A - sp.dot(self.B, self.C)) + (self.D[0]  
>> - 1) * den)
>> +
>> +        return (sp.roots(num))
>> +
>>    # Negation of a system
>>    def __neg__(self):
>>        """Negate a state space system"""
>>
>> Modified: trunk/src/xferfcn.py
>> ===================================================================
>> --- trunk/src/xferfcn.py    2010-06-01 02:08:20 UTC (rev 20)
>> +++ trunk/src/xferfcn.py    2010-06-06 17:29:42 UTC (rev 21)
>> @@ -190,6 +190,10 @@
>>
>>        return mag, phase, omega
>>
>> +    # Compute poles and zeros
>> +    def poles(self): return sp.roots(self.den)
>> +    def zeros(self): return sp.roots(self.num)
>> +
>>    # Feedback around a transfer function
>>    def feedback(sys1, sys2, sign=-1):
>>        """Feedback interconnection between two transfer functions"""
>>
>>
>> This was sent by the SourceForge.net collaborative development  
>> platform, the world's largest Open Source development site.
>
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