def testNegativeAssertions(self):
with self.assertRaises(BitWeightRangeError):
unused_v = BitWeight(-.5)
with self.assertRaises(BitWeightRangeError):
unused_v = BitWeight(-1, 2)
with self.assertRaises(BitWeightRangeError):
unused_v = BitWeight(1, -2)
with self.assertRaises(BitWeightRangeError):
unused_v = BitWeight(1, 0)
def setUp(self):
self.tiny = BitWeight(1, 1e6)
self.half = BitWeight(.5)
self.quarter = BitWeight(.25)
self.eighth = BitWeight(.125)
self.century = BitWeight(100)
self.millenium = BitWeight(1000)
class TestBitWeight(unittest.TestCase):
def setUp(self):
self.tiny = BitWeight(1, 1e6)
self.half = BitWeight(.5)
self.quarter = BitWeight(.25)
self.eighth = BitWeight(.125)
self.century = BitWeight(100)
self.millenium = BitWeight(1000)
def testNegativeAssertions(self):
with self.assertRaises(BitWeightRangeError):
unused_v = BitWeight(-.5)
with self.assertRaises(BitWeightRangeError):
unused_v = BitWeight(-1, 2)
with self.assertRaises(BitWeightRangeError):
unused_v = BitWeight(1, -2)
with self.assertRaises(BitWeightRangeError):
unused_v = BitWeight(1, 0)
def testAddition(self):
three_quarters = .75
self.assertEqual((self.half + self.quarter).real(), .75)
self.assertEqual((self.quarter + self.half).real(), .75)
# test the code path for equal values
self.assertEqual((self.quarter + self.quarter).real(), 0.5)
def testMultiplication(self):
one_quarter = .125
self.assertEqual((self.half * self.quarter).real(), .125)
self.assertEqual((self.quarter * self.half).real(), .125)
def testDivision(self):
self.assertEqual((self.half / self.quarter).real(), 2.)
self.assertEqual((self.quarter / self.half).real(), .5)
def testEquality(self):
my_half = BitWeight(1, 2)
self.assertEqual(self.half, my_half)
self.assertEqual(self.half.real(), my_half.real())
my_quarter = BitWeight(1, 4)
self.assertEqual(self.quarter, my_quarter)
self.assertEqual(self.quarter.real(), my_quarter.real())
def testComparison(self):
bws = [self.quarter, self.half, self.eighth]
bws.sort()
self.assertEqual([bw.real() for bw in bws], [.125, .25, .5])
def testEquality(self):
my_half = BitWeight(1, 2)
self.assertEqual(self.half, my_half)
self.assertEqual(self.half.real(), my_half.real())
my_quarter = BitWeight(1, 4)
self.assertEqual(self.quarter, my_quarter)
self.assertEqual(self.quarter.real(), my_quarter.real())
def set_viterbi(self):
VB = defaultdict(BitWeight)
TO = defaultdict(BitWeight)
NN = defaultdict(BitWeight)
PPSS = defaultdict(BitWeight)
VB = {
"name": "VB",
"start": BitWeight(.019),
"VB": BitWeight(.0038),
"TO": BitWeight(.83),
"NN": BitWeight(.0040),
"PPSS": BitWeight(.23)
}
TO = {
"name": "TO",
"start": BitWeight(0.0043),
"VB": BitWeight(0.035),
"TO": BitWeight(0.),
"NN": BitWeight(0.016),
"PPSS": BitWeight(0.00079)
}
NN = {
"name": "NN",
"start": BitWeight(0.041),
"VB": BitWeight(0.047),
"TO": BitWeight(0.00047),
"NN": BitWeight(0.087),
"PPSS": BitWeight(0.0012)
}
PPSS = {
"name": "PPSS",
"start": BitWeight(0.067),
"VB": BitWeight(0.007),
"TO": BitWeight(0.),
"NN": BitWeight(0.0045),
"PPSS": BitWeight(0.00014)
}
transitions = [VB, TO, NN, PPSS]
I = defaultdict(BitWeight)
want = defaultdict(BitWeight)
to = defaultdict(BitWeight)
race = defaultdict(BitWeight)
I = {
"name": "I",
"VB": BitWeight(0.),
"TO": BitWeight(0.),
"NN": BitWeight(0.),
"PPSS": BitWeight(.37)
}
want = {
"name": "want",
"VB": BitWeight(0.0093),
"TO": BitWeight(0.),
"NN": BitWeight(0.000054),
"PPSS": BitWeight(0.)
}
to = {
"name": "to",
"VB": BitWeight(0.),
"TO": BitWeight(0.99),
"NN": BitWeight(0.),
"PPSS": BitWeight(0.)
}
race = {
"name": "race",
"VB": BitWeight(0.00012),
"TO": BitWeight(0.),
"NN": BitWeight(0.00057),
"PPSS": BitWeight(0.)
}
emissions = [I, want, to, race]
for s in transitions:
if s["name"] == self.cur_state:
tprob = s[self.pointer.cur_state]
break
for e in emissions:
if e["name"] == self.cur_obs:
eprob = e[self.cur_state]
break
self.viterbi = (eprob * tprob)
def __init__(self, cur_state, cur_obs, cur_time, pointer):
self.cur_state = cur_state
self.cur_obs = cur_obs
self.cur_time = cur_time
self.pointer = pointer
self.viterbi = BitWeight(0.)
states = ['VB', 'TO', 'NN', 'PPSS']
cur_time = 0
initial = LatticeNode('start', "#", cur_time, None)
lattice = list()
previous = initial
best = initial
for s in states:
n = LatticeNode(s, obs[cur_time], cur_time, previous)
lattice.append(n)
n.set_viterbi()
if best.viterbi < n.viterbi:
best = n
previous = best
cur_time += 1
while cur_time < len(obs):
best.viterbi = BitWeight(0.)
for s in states:
n = LatticeNode(s, obs[cur_time], cur_time, previous)
lattice.append(n)
n.set_viterbi()
if best.viterbi < n.viterbi:
best = n
previous = best
cur_time += 1
p = lattice[-1]
tagseq = list()
while p.cur_state != "start":
tagseq.append(p.pointer)
p = p.pointer