mirror of
https://github.com/moses-smt/mosesdecoder.git
synced 2024-10-27 11:59:52 +03:00
28 lines
783 B
Python
28 lines
783 B
Python
#!/usr/bin/env python
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from math import exp,log
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class BleuScoreException(Exception):
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pass
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class BleuScorer:
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def __init__(self):
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"""References should be a list. If each element is a string, assume
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they are filenames, if a list, assume tokenised strings"""
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self.smooth = 1.0
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self.order = 4
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def score(self,scores):
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if len(scores) != self.order*2+1:
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raise BleuScoreException("Wrong number of scores. Expected %d, but found %d" %
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(self.order*2+1, len(scores)))
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logbleu = 0.0
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for j in range(self.order):
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logbleu += log(scores[2*j] + self.smooth) - log(scores[2*j+1] + self.smooth)
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logbleu /= self.order
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brevity = 1.0 - float(scores[-1]) / scores[1]
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if brevity < 0:
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logbleu += brevity
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return exp(logbleu)
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