public HashMap<Integer, ArrayList<Double>>  createFeatureMatrix(int vocabSize,int embeddingDimension) throws NullPointerException
    /*
     *Weight vector for each of the word is initialized here.
     */
    {
        HashMap<Integer, ArrayList<Double>>  featureMatrix = new HashMap<Integer, ArrayList<Double>>();
        for(int i =0 ; i< vocabSize; i++){
            featureMatrix.put(i,wordFeauture(embeddingDimension));
        }
        return featureMatrix;
    }//end of createFeatureMatrix



private ArrayList<Double> wordFeauture(int a) {
        Double ranVal;
        Random rand = new Random();
        ArrayList<Double> arrList = new ArrayList<Double>();
        for(int i =0 ; i< a; i++){
            ranVal = rand.nextGaussian();
            arrList.add(ranVal);
        }
        return arrList;
    }


   private ArrayList<Double> getContextFeatureVector(ArrayList<String> Ngram,HashMap<String,Integer > FrequentWordIndex,
                                              HashMap<Integer, ArrayList<Double> > wordFeatureMatrix) throws NullPointerException
    /*INPUT  :Ngram, Vocabulary Index
     *RETURNS:Feature Vector of context of given N-gram.
     */
    {
        int contextSize = Ngram.size()-1;
        System.out.println("getContextFeatureVector: Context Size:"+ contextSize);
        System.out.println(Ngram);
        ArrayList<Double> contextFeature = new ArrayList<Double>();
        contextFeature =wordFeatureMatrix.get(FrequentWordIndex.get(Ngram.get(0).toLowerCase()));
        System.out.println(Ngram.get(0));
        //System.out.println(contextFeature);

        for(int i =1 ; i < contextSize; i++){
            //ArrayList<Double> arrList = new ArrayList<Double>();
            System.out.println(Ngram.get(i));
            //arrList = wordFeatureMatrix.get(FrequentWordIndex.get(Ngram.get(i).toLowerCase()));
            System.out.println(wordFeatureMatrix.get(FrequentWordIndex.get(Ngram.get(i).toLowerCase())).size());
            //System.out.println("getContextFeatureVector:feature vector:"+arrList);
            //System.out.println("getContextFeatureVector:feature vector size:"+arrList.size());
             //contextFeature.addAll(wordFeatureMatrix.get(FrequentWordIndex.get(Ngram.get(i).toLowerCase())));
            //System.out.println("getContextFeatureVector:context vector size:"+contextFeature.size());
        }
        //System.out.println(contextFeature);
        System.out.println("Size of context Feature"+contextFeature.size());
        return contextFeature;
    }