code: def von_neumann_entropy(self, t_max=100):
          
          t = np.arange(t_max)
          return t, vne.compute_von_neumann_entropy(self.diff_op, t_max=t_max)
docs: Calculate Von Neumann Entropy
  
          Determines the Von Neumann entropy of the diffusion affinities
          at varying levels of `t`. The user should select a value of `t`
          around the "knee" of the entropy curve.
  
          We require that 'fit' stores the value of `PHATE.diff_op`
          in order to calculate the Von Neumann entropy.
  
          Parameters
          ----------
          t_max : int, default: 100
              Maximum value of `t` to test
  
          Returns
          -------
          entropy : array, shape=[t_max]
              The entropy of the diffusion affinities for each value of `t`