Source Code for Module featuregenerator.ratio_generator

 1  """ 
 2   
 3  @author: Eleftherios Avramidis 
 4  """ 
 5  from __future__ import division 
 6  from featuregenerator import FeatureGenerator 
 7  from nltk.tokenize.punkt import PunktWordTokenizer 
 8   
 9   
10 -class RatioGenerator(FeatureGenerator): 
11      """ 
12      Computes the ratio of source features and target features, if they have the same name 
13      """ 
14   
15       
16 -    def get_features_tgt(self, simplesentence, parallelsentence): 
17          #get the length of the source 
18          tgt_attributes = simplesentence.get_attributes() 
19          src_attributes = parallelsentence.get_source().get_attributes() 
20           
21          attributes = {} 
22           
23          #if there are two features with the same name in bot src and target, calculate their ratio and add it 
24          for tgt_attribute_name in tgt_attributes.keys(): 
25              if tgt_attribute_name in src_attributes.keys(): 
26                  try: 
27                      new_attribute_name = "%s_ratio" % tgt_attribute_name 
28                      if new_attribute_name not in tgt_attributes.keys(): 
29                          #do calculations only if needed 
30                          tgt_attribute_value = float(tgt_attributes[tgt_attribute_name]) 
31                          src_attribute_value = float(src_attributes[tgt_attribute_name]) 
32                          if tgt_attribute_value == 0: 
33                              ratio = float('inf') 
34                          else: 
35                              ratio = 1.0 * src_attribute_value / tgt_attribute_value 
36                          attributes[new_attribute_name] = str(ratio) 
37                  except ValueError: 
38                      pass 
39                       
40                       
41          return attributes 
42