def test_prob2(self):
tagset = {'D', 'N', 'V'}
trans = {
('<s>', '<s>'): {
'D': 1.0
},
('<s>', 'D'): {
'N': 1.0
},
('D', 'N'): {
'V': 0.8,
'N': 0.2
},
('N', 'N'): {
'V': 1.0
},
('N', 'V'): {
'</s>': 1.0
},
}
out = defaultdict(
float, {
'D': {
'the': 1.0
},
'N': {
'dog': 0.4,
'barks': 0.6
},
'V': {
'dog': 0.1,
'barks': 0.9
},
})
hmm = HMM(3, tagset, trans, out)
x = 'the dog barks'.split()
y = 'D N V'.split()
p = hmm.prob(x, y)
self.assertAlmostEqual(p, 0.8 * 0.4 * 0.9)
lp = hmm.log_prob(x, y)
self.assertAlmostEqual(lp, log2(0.8 * 0.4 * 0.9))
def test_prob(self):
tagset = {'D', 'N', 'V'}
trans = {
('<s>', '<s>'): {'D': 1.0},
('<s>', 'D'): {'N': 1.0},
('D', 'N'): {'V': 1.0},
('N', 'V'): {'</s>': 1.0},
}
out = defaultdict(float, {
'D': {'the': 1.0},
'N': {'dog': 0.4, 'barks': 0.6},
'V': {'dog': 0.1, 'barks': 0.9},
})
hmm = HMM(3, tagset, trans, out)
x = 'the dog barks'.split()
y = 'D N V'.split()
p = hmm.prob(x, y)
self.assertAlmostEqual(p, 0.4 * 0.9)
lp = hmm.log_prob(x, y)
self.assertAlmostEqual(lp, log2(0.4 * 0.9))
