Q.match_query_to_corpus() -> index -- return the matched corpus 
		index of the user query

def match_query_to_corpus(self):
		"""Q.match_query_to_corpus() -> index -- return the matched corpus 
		index of the user query 
		"""
		ranking = []
		for i,doc in enumerate(self.processed_corpus):
			rank = 0.0
			for word in self.processed_query:
				if word in doc:
					rank += self.term_frequencies[i][word] * self.inverse_document_frequencies[word]
			ranking.append((rank,i))
		matching_corpus_index = 0
		max_rank = 0
		for rank,index in ranking:
			if rank > max_rank:
				matching_corpus_index = index
				max_rank = rank
		return matching_corpus_index