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Changes in preparation for using v0.4 as trunk:
* Added missing MATLAB compatible functions for module reduction * Turned off print statements in unit tests (turn back on using verbose flag) * Removed bug warnings from conversion routines; posted open bug to Pending * Updated examples/pvtol-nested-ss to reflect interface changes * See ChangeLog for a detailed list of changes
1 parent 0f31ff6 commit 55df572

12 files changed

Lines changed: 86 additions & 58 deletions

‎ChangeLog‎

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@@ -1,5 +1,31 @@
11
2011-04-02 Richard Murray <murray@malabar.local>
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* src/__init__.py: removed import of tests module (moved to tests/)
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* src/matlab.py: Added hsvd, balred, modred to list of functions
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that are imported for use as is. Updated documentation string to
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indicate that these are implemented, along with a few other
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functions (zero, lqr) that weren't properly listed.
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* src/modelsimp.py (balred): Removed extraneous print statements
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(modred): Set method to be 'matchdc' by default (to match MATLAB)
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* src/__init__.py: added missing import of modelsimp functions
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* tests/slycot_convert_test.py (TestSlycot.testTF): turned off print
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statements in unit test to make it easier to see results. Use
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verbose=True to turn back on.
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* tests/convert_test.py (TestConvert.testConvert): got rid of print
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statements in unittest; clutters the output so that you can't see
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the errors clearly. Use verbose=True to turn back on.
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* src/statesp.py (_convertToStateSpace): removed "buggy" print
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statements
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* src/xferfcn.py (_convertToTransferFunction): removed "buggy" print
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statements
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* tests/nichols_test.py (TestStateSpace.testNgrid): updated testcode
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to turn off grid in initial Nichols chart plot.
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‎Pending‎

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Original file line numberDiff line numberDiff line change
@@ -10,9 +10,9 @@ picture" things that need to be done.
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1111
OPEN BUGS
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* matlab.step() doesn't handle systems with a pole at the origin (use lsim2)
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* tests/convert_test.py not working yet
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* tests/test_all.py should report on failed tests
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* tests/freqresp.py needs to be converted to unit test
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* TF <-> SS transformations are buggy; see tests/convert_test.py
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* hsvd returns different value than MATLAB (2010a); see modelsimp_test.py
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* MIMO common denominator fails unit test; see convert_test.py
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Transfer code from Roberto Bucher's yottalab to python-control
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acker - pole placement using Ackermann method
@@ -40,6 +40,9 @@ Examples and test cases
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* Put together unit tests for all functions (after deciding on framework)
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* Figure out how to import 'figure' command properly (version issue?)
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* Figure out source of BadCoefficients warning messages (pvtol-lqr and others)
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* tests/test_all.py should report on failed tests
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* tests/freqresp.py needs to be converted to unit test
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* Convert examples/test-{response,statefbk}.py to unit tests
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TransferFunction class fixes
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* evalfr is not working (num, den stored as ndarrays, not poly1ds)

‎examples/pvtol-nested-ss.py‎

Lines changed: 9 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -95,21 +95,21 @@
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# (gm, pm, wgc, wpc) = margin(L);
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figure(6); clf; subplot(221);
98-
(magh, phaseh) = bode(L);
98+
bode(L, logspace(-4, 3));
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# Add crossover line
101-
subplot(magh); hold(True);
102-
loglog([10^-4, 10^3], [1, 1], 'k-')
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subplot(211); hold(True);
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loglog([1e-4, 1e3], [1, 1], 'k-')
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# Replot phase starting at -90 degrees
105-
bode(L, logspace(-4, 3));
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(mag, phase, w) = freqresp(L, logspace(-4, 3));
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phase = phase - 360;
108-
subplot(phaseh);
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semilogx([10^-4, 10^3], [-180, -180], 'k-')
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subplot(212);
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semilogx([1e-4, 1e3], [-180, -180], 'k-')
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hold(True);
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semilogx(w, np.squeeze(phase), 'b-')
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axis([10^-4, 10^3, -360, 0]);
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axis([1e-4, 1e3, -360, 0]);
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xlabel('Frequency [deg]'); ylabel('Phase [deg]');
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# set(gca, 'YTick', [-360, -270, -180, -90, 0]);
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# set(gca, 'XTick', [10^-4, 10^-2, 1, 100]);
@@ -152,8 +152,8 @@
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#TODO: PZmap for statespace systems has not yet been implemented.
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figure(10); clf();
155-
#(P, Z) = pzmap(T, Plot=True)
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#print "Closed loop poles and zeros: ", P, Z
155+
# (P, Z) = pzmap(T, Plot=True)
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# print "Closed loop poles and zeros: ", P, Z
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# Gang of Four
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figure(11); clf();

‎src/__init__.py‎

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@@ -63,5 +63,4 @@
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from bdalg import *
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from statefbk import *
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from delay import *
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67-
from test import *
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from modelsimp import *

‎src/matlab.py‎

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@@ -80,6 +80,7 @@
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from pzmap import pzmap
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from statefbk import ctrb, obsv, gram, place, lqr
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from delay import pade
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from modelsimp import hsvd, balred, modred
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__doc__ += """
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The control.matlab module defines functions that are roughly the
@@ -139,9 +140,9 @@
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lti/bandwidth - system bandwidth
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lti/norm - h2 and Hinfinity norms of LTI models
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\* lti/pole - system poles
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lti/zero - system (transmission) zeros
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\* lti/zero - system (transmission) zeros
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lti/order - model order (number of states)
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\* pzmap - pole-zero map
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\* pzmap - pole-zero map (TF only)
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lti/iopzmap - input/output pole-zero map
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damp - natural frequency and damping of system poles
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esort - sort continuous poles by real part
@@ -173,19 +174,20 @@
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Model simplification
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minreal - minimal realization and pole/zero cancellation
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ss/sminreal - structurally minimal realization (state space)
176-
lti/hsvd - hankel singular values (state contributions)
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lti/balred - reduced-order approximations of LTI models
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ss/modred - model order reduction
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\* lti/hsvd - hankel singular values (state contributions)
178+
\* lti/balred - reduced-order approximations of LTI models
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\* ss/modred - model order reduction
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Compensator design
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rlocus - evans root locus
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place - pole placement
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\* place - pole placement
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estim - form estimator given estimator gain
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reg - form regulator given state-feedback and estimator gains
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LQR/LQG design
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ss/lqg - single-step LQG design
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lqr, dlqr - linear-Quadratic (LQ) state-feedback regulator
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\* lqr - linear-Quadratic (LQ) state-feedback regulator
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\* dlqr - discrete-time LQ state-feedback regulator
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lqry - lq regulator with output weighting
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lqrd - discrete LQ regulator for continuous plant
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ss/lqi - linear-Quadratic-Integral (LQI) controller

‎src/modelsimp.py‎

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@@ -84,7 +84,7 @@ def hsvd(sys):
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# Return the Hankel singular values
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return hsv
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87-
def modred(sys,ELIM,method):
87+
def modred(sys,ELIM,method='matchdc'):
8888
"""Model reduction of sys by eliminating the states in ELIM using a given method
8989
9090
Parameters
@@ -207,8 +207,8 @@ def balred(sys,orders,method='truncate'):
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208208
#Check system is stable
209209
D,V = np.linalg.eig(sys.A)
210-
print D.shape
211-
print D
210+
# print D.shape
211+
# print D
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for e in D:
213213
if e.real >= 0:
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raise ValueError, "Oops, the system is unstable!"

‎src/statesp.py‎

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@@ -469,8 +469,6 @@ def _convertToStateSpace(sys, **kw):
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# Repeat the common denominator along the rows.
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den = array([den for i in range(sys.outputs)])
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# TODO: transfer function to state space conversion is still buggy!
472-
print "Warning: transfer function to state space conversion by td04ad \
473-
is still buggy! Advise converting state space sys back to tf to verify the transformation was correct."
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#print num
475473
#print shape(num)
476474
ssout = td04ad('R',sys.inputs, sys.outputs, index, den, num,tol=0.0)

‎src/xferfcn.py‎

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@@ -713,8 +713,6 @@ def _convertToTransferFunction(sys, **kw):
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# Use Slycot to make the transformation. TODO: this is still somewhat
715715
# buggy!
716-
print "Warning: state space to transfer function conversion by tb04ad \
717-
is still buggy!"
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tfout = tb04ad(sys.states, sys.inputs, sys.outputs, sys.A, sys.B, sys.C,
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sys.D,tol1=0.0)
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@@ -727,8 +725,8 @@ def _convertToTransferFunction(sys, **kw):
727725
num[i][j] = list(tfout[6][i, j, :])
728726
# Each transfer function matrix row has a common denominator.
729727
den[i][j] = list(tfout[5][i, :])
730-
print num
731-
print den
728+
# print num
729+
# print den
732730
return TransferFunction(num, den)
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elif isinstance(sys, (int, long, float, complex)):
734732
if "inputs" in kw:

‎tests/convert_test.py‎

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@@ -1,6 +1,6 @@
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#!/usr/bin/env python
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3-
"""TestConvert.py
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"""convert_test.py
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Test state space and transfer function conversion.
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@@ -40,7 +40,7 @@ def printSys(self, sys, ind):
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print "sys%i:\n" % ind
4141
print sys
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43-
def testConvert(self):
43+
def testConvert(self, verbose=0):
4444
"""Test state space to transfer function conversion."""
4545
#Currently it only tests that a TF->SS->TF generates an unchanged TF
4646

@@ -52,16 +52,20 @@ def testConvert(self):
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#start with a random SS system and transform to TF
5353
#then back to SS, check that the matrices are the same.
5454
ssOriginal = matlab.rss(states, inputs, outputs)
55-
self.printSys(ssOriginal, 1)
55+
if (verbose):
56+
self.printSys(ssOriginal, 1)
5657

5758
tfOriginal = matlab.tf(ssOriginal)
58-
self.printSys(tfOriginal, 2)
59+
if (verbose):
60+
self.printSys(tfOriginal, 2)
5961

6062
ssTransformed = matlab.ss(tfOriginal)
61-
self.printSys(ssTransformed, 3)
63+
if (verbose):
64+
self.printSys(ssTransformed, 3)
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6366
tfTransformed = matlab.tf(ssTransformed)
64-
self.printSys(tfTransformed, 4)
67+
if (verbose):
68+
self.printSys(tfTransformed, 4)
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6670
for inputNum in range(inputs):
6771
for outputNum in range(outputs):
@@ -81,8 +85,6 @@ def testConvert(self):
8185
#[mag,phase,freq]=bode(sys)
8286
#it doesn't seem to......
8387
#This should be added.
84-
85-
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8789
def suite():
8890
return unittest.TestLoader().loadTestsFromTestCase(TestConvert)

‎tests/modelsimp_test.py‎

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@@ -16,7 +16,7 @@ def testHSVD(self):
1616
D = np.matrix("9.")
1717
sys = ss(A,B,C,D)
1818
hsv = hsvd(sys)
19-
hsvtrue = np.matrix("24.42686 0.5731395")
19+
hsvtrue = np.matrix("24.42686 0.5731395") # from MATLAB
2020
np.testing.assert_array_almost_equal(hsv, hsvtrue)
2121

2222
def testMarkov(self):

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