public static void ReadFromFile(String fileName){       
        BufferedReader br = null;
        try{
            br = new BufferedReader(new FileReader(fileName));
            String line = null;
            while((line = br.readLine()) != null){
                HashMap<Integer, ArrayList<Double>> geneEntry = new HashMap<Integer, ArrayList<Double>>();
                ArrayList<Double> gene = new ArrayList<Double>();
                String[] values = line.split("\t");
                if(Integer.parseInt(values[1]) > -1){
                    externalIndex.put(Integer.parseInt(values[0]), Integer.parseInt(values[1]));
                    for(int i = 2; i < values.length; i++){
                        gene.add(Double.parseDouble(values[i]));
                    }
                    geneEntry.put(Integer.parseInt(values[0]), gene);
                    geneList.add(geneEntry);
                }
            }
            br.close();
        }catch(FileNotFoundException e1){
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }catch(IOException e){
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }