code: def scramble_positions(p, delete_frac=0.1):
      
      probs = [1-delete_frac, delete_frac]
      m = np.random.choice([True, False], p.shape[0], p=probs)
      jumble = np.random.randn(m.sum(), 3)
      return p[m] + jumble
docs: randomly deletes particles and adds 1-px noise for a realistic
      initial featuring guess