Source code for nordlys.logic.el.greedy

Generative model for interpretation set finding

@author: Faegheh Hasibi

from __future__ import division

from import Instances

[docs]class Greedy(object): def __init__(self, score_th): self.__score_th = score_th
[docs] def disambiguate(self, inss): """ Takes instances and generates set of entity linking interpretations. :param inss: Instances object :return: sets of interpretations [{mention: (en_id, score), ..}, ...] """ pruned_inss = self.prune_by_score(inss) pruned_inss = self.prune_containment_mentions(pruned_inss) interpretations = self.create_interpretations(pruned_inss) return interpretations
[docs] def prune_by_score(self, query_inss): """ prunes based on a static threshold of ranking score.""" valid_inss = [] for ins in query_inss.get_all(): if ins.score >= self.__score_th: valid_inss.append(ins) return Instances(valid_inss)
[docs] def prune_containment_mentions(self, query_inss): """Deletes containment mentions, if they have lower score.""" if len(query_inss.get_all()) == 0: return query_inss valid_inss = [] #dict() # {mention: ins} valid_mens = set() for ins in sorted(query_inss.get_all(), key=lambda item: item.score, reverse=True): is_contained = False cand_men = ins.get_property("mention") for men in valid_mens: if (cand_men != men) and ((cand_men in men) or (men in cand_men)): is_contained = True if not is_contained: # valid_inss[ins.get_property("mention")] = ins valid_inss.append(ins) valid_mens.add(ins.get_property("mention")) # @todo: This line should be fixed return Instances(valid_inss) #list(valid_inss.values()))
[docs] def create_interpretations(self, query_inss): """ Groups CER instances as interpretation sets. :return list of interpretations, where each interpretation is a dictionary {mention: (en_id, score), ..} """ interpretations = [dict()] # list of dictionaries {men: ins} for ins in sorted(query_inss.get_all(), key=lambda item:item.score, reverse=True): added = False for inter in interpretations: mentions = list(inter.keys()) mentions.append(ins.get_property("mention")) if not self.is_overlapping(mentions): inter[ins.get_property("mention")] = (ins.get_property("en_id"), ins.score) added = True if not added: interpretations.append({ins.get_property("mention"): (ins.get_property("en_id"), ins.score)}) return interpretations
[docs] def is_overlapping(self, mentions): """ Checks whether the strings of a set overlapping or not. i.e. if there exists a term that appears twice in the whole set. E.g. {"the", "music man"} is not overlapping {"the", "the man", "music"} is overlapping. NOTE: If a query is "yxxz" the mentions {"yx", "xz"} and {"yx", "x"} are overlapping. :param mentions: A list of strings :return True/False """ word_list = [] for mention in mentions: word_list += set(mention.split()) if len(word_list) == len(set(word_list)): return False else: return True