public void createVectors() {
        for(int i = 0; i < FREE_DOC_ID; i++) {
             Vector<Double> vec = new Vector<>();
            for(Entry elem: tf_Idf.entrySet()){
                HashMap<Integer, Double> map = (HashMap<Integer, Double>)elem.getValue();
                if(map.containsKey(i)) {
                    vec.add(map.get(i));
                }
            }
            Double vecLntg = 0d;
            for(Double elem: vec) {
                vecLntg += Math.pow(elem, 2);
            }
            vecLenght.put(i, Math.sqrt(vecLntg));
            docVec.put(i, vec);
        }
    }