相似性计算

 

public double CosSim(HashMap<String, Double> hashA,HashMap<String, Double> hashB,double sa,double sb)
	{
	    double sum=0;
	    HashMap<String, Double> tmp=null;
	    if (hashA.size()>hashB.size())
	    {
	    	tmp=hashA;
	    	hashA=hashB;
	    	hashB=tmp;
	    }
	    java.util.Iterator<String> iterator = hashA.keySet().iterator();
		while (iterator.hasNext())
		{
			String word = iterator.next();
			if(hashB.containsKey(word))
			{
				sum=sum+hashA.get(word)*hashB.get(word);
			}
		}
		sum=sum/(sa*sb);
	    return sum;
	
	}