Find Similar users

def self.get_potentials(interest_ids)
	  return {} if interest_ids.nil? ||interest_ids.empty?
	  map = <<-eos
function() {
	for(var i in this.value.users) {
		emit(this.value.users[i], 1);
	}	
};
eos
	  reduce = <<-eos
function(key, emits) {
	var count = 0;
	for(var i in emits) {
		count += emits[i];
	}
	return count;
};
	  eos
	  users = InterestMap.collection.map_reduce(map, reduce, 
				{:query => {:_id => {:$in => interest_ids}} }).find().to_a
    
	  users.inject({}) do |h,user| 
		  h[user["_id"].to_i] = user["value"]
		  h
	  end
  end