Calculate Jaccard Similarity.
     
    
    Usage
    jaccardSim(idsInSet, score)
 
    
    Arguments
- idsInSet
- A list of set names and their member IDs. 
- score
- A vector of addible scores with the same length used to assign input preference;
higher score has larger weight, i.e. -logP. 
 
    
    Value
    A list of similarity matrix sim.mat and input preference vector ip.vec.
     
    
    Author
    Zhiao Shi, Yuxing Liao