private Map<Integer, Double> getMappedTextFile(String txtFile){
        BufferedReader br = null;
        Map<Integer, Double> file1List = new TreeMap<Integer, Double>();
        
        try {
            br = new BufferedReader(new FileReader(txtFile));
            String line = br.readLine();
            while (line != null) {
                Object[] rowfields = line.split("\t");
                file1List.put(Integer.parseInt(rowfields[0].toString()), Double.parseDouble(rowfields[1].toString()));
                line = br.readLine();
            }

        } catch (IOException ex) {
            Logger.getLogger(LSInSVD.class.getName()).log(Level.SEVERE, null, ex);
        }
        return file1List;
    }