Skip to content

Fix slycot zero #219

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
murrayrm merged 2 commits into from
Jul 7, 2018
Merged

Fix slycot zero #219

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
7b04c01
add unit test for state space system with no transmission zero
murrayrm Jul 7, 2018
87ec281
fix empty transmission zero bug for state space systems
murrayrm Jul 7, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 5 additions & 1 deletion control/statesp.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -525,7 +525,11 @@ def zero(self):
out = ab08nd(self.A.shape[0], self.B.shape[1], self.C.shape[0],
self.A, self.B, self.C, self.D)
nu = out[0]
return sp.linalg.eigvals(out[8][0:nu,0:nu], out[9][0:nu,0:nu])
if nu == 0:
return np.array([])
else:
return sp.linalg.eigvals(out[8][0:nu,0:nu], out[9][0:nu,0:nu])

except ImportError: # Slycot unavailable. Fall back to scipy.
if self.C.shape[0] != self.D.shape[1]:
raise NotImplementedError("StateSpace.zero only supports "
Expand Down
5 changes: 5 additions & 0 deletions control/tests/statesp_test.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,11 @@ def testPole(self):

np.testing.assert_array_almost_equal(p, true_p)

def testEmptyZero(self):
"""Test to make sure zero() works with no zeros in system"""
sys = _convertToStateSpace(TransferFunction([1], [1,2,1]))
np.testing.assert_array_equal(sys.zero(), np.array([]))

@unittest.skipIf(not slycot_check(), "slycot not installed")
def testMIMOZero_nonsquare(self):
"""Evaluate the zeros of a MIMO system."""
Expand Down