code: def _shrink(v, gamma):
          
          pos = v > gamma
          neg = v < -gamma
          v[pos] -= gamma
          v[neg] += gamma
          v[np.logical_and(~pos, ~neg)] = .0
          return v
docs: Soft-shrinkage of an array with parameter gamma.
  
          Parameters
          ----------
  
          v : array
              Array containing the values to be applied to the shrinkage operator
  
          gamma : float
              Shrinkage parameter.
  
          Returns
          -------
  
          v : array
              The same input array after the shrinkage operator was applied.