code: public static ClassificationDataSet loadC(File file, double sparseRatio) throws FileNotFoundException, IOException
      {
          return loadC(file, sparseRatio, -1);
      }
docs: Loads a new classification data set from a LIBSVM file, assuming the
  label is a nominal target value
  
  @param file the file to load
  @param sparseRatio the fraction of non zero values to qualify a data
  point as sparse
  @return a classification data set
  @throws FileNotFoundException if the file was not found
  @throws IOException if an error occurred reading the input stream