Merge pull request #525 from bnavigator/fix-523 · python-control/python-control@649215e
@@ -338,13 +338,19 @@ def test_zmore_stability_margins(tsys_zmore):
338338 'cnum, cden, dt,'
339339 'ref,'
340340 'rtol',
341- [([2], [1, 3, 2, 0], 1e-2, # gh-465
342- (2.9558, 32.8170, 0.43584, 1.4037, 0.74953, 0.97079),
343- 0.1 # very crude tolerance, because the gradients are not great
344- ),
345- ([2], [1, 3, 3, 1], .1, # 2/(s+1)**3
346- [3.4927, 69.9996, 0.5763, 1.6283, 0.7631, 1.2019],
347- 1e-3)])
341+ [( # gh-465
342+ [2], [1, 3, 2, 0], 1e-2,
343+ [2.9558, 32.390, 0.43584, 1.4037, 0.74951, 0.97079],
344+ 2e-3), # the gradient of the function reduces numerical precision
345+ ( # 2/(s+1)**3
346+ [2], [1, 3, 3, 1], .1,
347+ [3.4927, 65.4212, 0.5763, 1.6283, 0.76625, 1.2019],
348+ 1e-4),
349+ ( # gh-523
350+ [1.1 * 4 * np.pi**2], [1, 2 * 0.2 * 2 * np.pi, 4 * np.pi**2], .05,
351+ [2.3842, 18.161, 0.26953, 11.712, 8.7478, 9.1504],
352+ 1e-4),
353+ ])
348354def test_stability_margins_discrete(cnum, cden, dt, ref, rtol):
349355"""Test stability_margins with discrete TF input"""
350356tf = TransferFunction(cnum, cden).sample(dt)