code: def _dichopsi_log(u, v, y, eps=0.00001):
      """Implements the dichotomic part of the solution of psi(c)-log(c)=y"""
      if u > v:
          u, v = v, u
      t = (u + v) / 2
      if np.absolute(u - v) < eps:
          return t
      else:
          if sp.psi(t) - np.log(t) > y:
              return _dichopsi_log(u, t, y, eps)
          else:
              return _dichopsi_log(t, v, y, eps)
  
imports: import numpy
  import scipy.special
  import scipy.stats
label_desc: Use image node_id 1 for calling a global function with example usage: _dichopsi_log(u, v, y, eps) and returns: t, _dichopsi_log, _dichopsi_log