public static void testLoadingData(String[] args) {
    System.out.println("Loading point cloud from data: ex 0");
    if (args.length < 1) {
      System.out.println("Usage: java ImageManipulation filename.dat");
      System.exit(0);
    }
    // load point cloud
    PointCloud N;
    // N=PointCloud.randomPoints(10000, 3);
    N = Clustering.readFile(args[0]);

    Draw.draw2D(N, "original point cloud");
    Draw.draw3D(N);
  }