private Kernel getKernel (KernelType kType) {
    Kernel k = null;
    double width = 1.4;
    int cache_size = 10;
    switch (kType) {
      case GAUSSIAN:
        k = new GaussianKernel (10, width);
        break;
      case HIK:
        double beta = 1.4;
        HistogramIntersectionKernel hik = new HistogramIntersectionKernel (cache_size);
        hik.set_beta (beta);
        k = hik;
        break;
      case POLY:
        int degree = 1;
        k = new PolyKernel (cache_size, degree);
        break;
      case CHI2:
        k = new Chi2Kernel (cache_size, width);
        break;
      default:
        System.err.println ("invalid kernel type!");
        System.exit (1);
    }
    return k;
  }

  public void train (DoubleMatrix trainSet, Labels trainLabels) {
    double eps = 1e-5;
    double C = 1;

    RealFeatures trainFeats = new RealFeatures (trainSet);

    boolean slow = false;
    if (slow) {
      kernel = getKernel (kernelType);
      kernel.init (trainFeats, trainFeats);
    } else {
      kernel = new HistogramIntersectionKernel (trainFeats, trainFeats, 1.4);
    }
    ml = new LaRank (C, kernel, trainLabels);
   ((LaRank)ml).set_epsilon (eps);
    ml.train ();
  }