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update minreal unit test to use poles/zeros instead of num/den #220

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Merged
murrayrm merged 1 commit into from
Jul 7, 2018
Merged

update minreal unit test to use poles/zeros instead of num/den #220

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41 changes: 28 additions & 13 deletions control/tests/minreal_test.py
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Original file line number Diff line number Diff line change
Expand Up @@ -43,24 +43,39 @@ def testMinrealBrute(self):
if s.states > sr.states:
self.nreductions += 1
else:
# Check to make sure that poles and zeros match

# For poles, just look at eigenvalues of A
np.testing.assert_array_almost_equal(
np.sort(eigvals(s.A)), np.sort(eigvals(sr.A)))

# For zeros, need to extract SISO systems
for i in range(m):
for j in range(p):
ht1 = matlab.tf(
matlab.ss(s.A, s.B[:,i], s.C[j,:], s.D[j,i]))
ht2 = matlab.tf(
matlab.ss(sr.A, sr.B[:,i], sr.C[j,:], sr.D[j,i]))
try:
self.assert_numden_almost_equal(
ht1.num[0][0], ht2.num[0][0],
ht1.den[0][0], ht2.den[0][0])
except Exception as e:
# for larger systems, the tf minreal's
# the original rss, but not the balanced one
if n < 6:
raise e
# Extract SISO dynamixs from input i to output j
s1 = matlab.ss(s.A, s.B[:,i], s.C[j,:], s.D[j,i])
s2 = matlab.ss(sr.A, sr.B[:,i], sr.C[j,:], sr.D[j,i])

# Check that the zeros match
# Note: sorting doesn't work => have to do the hard way
z1 = matlab.zero(s1)
z2 = matlab.zero(s2)

# Start by making sure we have the same # of zeros
self.assertEqual(len(z1), len(z2))

# Make sure all zeros in s1 are in s2
for zero in z1:
# Find the closest zero
self.assertAlmostEqual(min(abs(z2 - zero)), 0.)

# Make sure all zeros in s2 are in s1
for zero in z2:
# Find the closest zero
self.assertAlmostEqual(min(abs(z1 - zero)), 0.)

# Make sure that the number of systems reduced is as expected
# (Need to update this number if you change the seed at top of file)
self.assertEqual(self.nreductions, 2)

def testMinrealSS(self):
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3 changes: 1 addition & 2 deletions control/xferfcn.py
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Expand Up @@ -1162,8 +1162,7 @@ def tf(*args):
tf2ss

Notes
--------

-----
``num[i][j]`` contains the polynomial coefficients of the numerator
for the transfer function from the (j+1)st input to the (i+1)st output.
``den[i][j]`` works the same way.
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