def test_discrete(sys):
dt = 0.001
alpha = 0.6
for method in ('gbt', 'bilinear', 'tustin', 'euler', 'forward_diff',
'backward_diff', 'zoh'):
dsys = cont2discrete(sys, dt=dt, method=method, alpha=alpha)
assert not dsys.analog
rsys = discrete2cont(dsys, dt=dt, method=method, alpha=alpha)
assert rsys.analog
assert ss_equal(sys, rsys, atol=1e-07)
def test_discrete(sys):
dt = 0.001
alpha = 0.6
for method in ('gbt', 'bilinear', 'tustin', 'euler', 'forward_diff',
'backward_diff', 'zoh'):
dsys = cont2discrete(sys, dt=dt, method=method, alpha=alpha)
assert not dsys.analog
rsys = discrete2cont(dsys, dt=dt, method=method, alpha=alpha)
assert rsys.analog
assert np.allclose(sys.ss[0], rsys.ss[0])
assert np.allclose(sys.ss[1], rsys.ss[1])
assert np.allclose(sys.ss[2], rsys.ss[2])
assert np.allclose(sys.ss[3], rsys.ss[3])
def test_invalid_discrete():
dt = 0.001
sys = cont2discrete(Lowpass(0.1), dt=dt)
with pytest.raises(ValueError):
discrete2cont(sys, dt=dt, method='gbt', alpha=1.1)
with pytest.raises(ValueError):
discrete2cont(sys, dt=0)
with pytest.raises(ValueError):
discrete2cont(sys, dt=dt, method=None)
with pytest.raises(ValueError):
discrete2cont(s, dt=dt) # already continuous
with pytest.raises(ValueError):
cont2discrete(z, dt=dt) # already discrete
def test_invalid_discrete():
dt = 0.001
sys = cont2discrete(Lowpass(0.1), dt=dt)
with pytest.raises(ValueError):
discrete2cont(sys, dt=dt, method='gbt', alpha=1.1)
with pytest.raises(ValueError):
discrete2cont(sys, dt=0)
with pytest.raises(ValueError):
discrete2cont(sys, dt=dt, method=None)
with pytest.raises(ValueError):
discrete2cont(s, dt=dt) # already continuous
with pytest.raises(ValueError):
cont2discrete(z, dt=dt) # already discrete
