def get_labels(self):
"""label each slot in the sausage (O=correct X=incorrect)"""
if self.correct():
# everything is correct
return ['O'] * self.num_slots()
# align the ref and the best hyp
a = Sequence(self.ref())
b = Sequence(self.best_hyp())
v = Vocabulary()
aEncoded = v.encodeSequence(a)
bEncoded = v.encodeSequence(b)
scoring = SimpleScoring(2, -1)
aligner = StrictGlobalSequenceAligner(scoring, -2)
score, encodeds = aligner.align(aEncoded, bEncoded, backtrace=True)
alignment = v.decodeSequenceAlignment(encodeds[0])
# get labels according to alignment
labels = []
for a, b in zip(alignment.first, alignment.second):
if a == b or a == '-' and b == '*DELETE*':
labels.append('O')
else:
labels.append('X')
return labels
def align_sequences(seq_a, seq_b):
# Must escape '-' because alignment library uses it as a gap
# marker.
escaped_seq_a = ['\\-' if x == '-' else x for x in seq_a]
escaped_seq_b = ['\\-' if x == '-' else x for x in seq_b]
v = Vocabulary()
encoded_a = v.encodeSequence(Sequence(escaped_seq_a))
encoded_b = v.encodeSequence(Sequence(escaped_seq_b))
scoring = SimpleScoring(matchScore=3, mismatchScore=-1)
aligner = StrictGlobalSequenceAligner(scoring, gapScore=-2)
_, encodeds = aligner.align(encoded_a, encoded_b, backtrace=True)
return encodeds[0]
