def test_simple_hmm(self):
"https://people.csail.mit.edu/rameshvs/content/hmms.pdf"
hidden_values = ['Area 1', 'Area 2', 'Area 3']
prior = {'Area 1': 1 / 3, 'Area 2': 1 / 3, 'Area 3': 1 / 3}
transition_table = {
'Area 1': {
'Area 1': 0.25,
'Area 2': 0.75,
'Area 3': 0.
},
'Area 2': {
'Area 1': 0.,
'Area 2': 0.25,
'Area 3': 0.75
},
'Area 3': {
'Area 1': 0.,
'Area 2': 0.,
'Area 3': 1.
},
}
obs_values = ['hot', 'cold']
obs_table = {
'Area 1': {
'hot': 1.0,
'cold': 0.0
},
'Area 2': {
'hot': 0.0,
'cold': 1.0
},
'Area 3': {
'hot': 1.0,
'cold': 0.0
},
}
hmm = HMM(hidden_values,
prior,
transition_table,
obs_values,
obs_table,
n_steps=3)
hmm.set_observed_values(['hot', 'cold', 'hot'])
hmm.compute_alpha()
result = hmm.filtered_posterior(index=2)
for r, v in zip(result.values(), [0.0, 0.0, 1.0]):
self.assertEqual(r, v)
hmm.compute_beta()
for r, v in zip(
hmm.smoothed_posterior(index=2).values(), [0.0, 0.0, 1.0]):
self.assertEqual(r, v)
