private double computeCosineSimilarity(HashMap<String, Double> scores1, HashMap<String, Double> scores2){
		double s1 = 0.0;
		for(String s : scores1.keySet()){
			s1+= scores1.get(s)*scores1.get(s);
		}
		
		double s2 = 0.0;
		for(String s : scores2.keySet()){
			s2+= scores2.get(s)*scores2.get(s);
		}
		
		double sum = 0.0;
		for(String s : scores2.keySet()){
			if(scores1.containsKey((s)))
				sum+= scores2.get(s) * scores1.get(s);		
		}
		return sum / (s1 * s2);
	}