code: def zero2d(self):
          
          return type(self)(x=np.atleast_2d(np.zeros((self.shape[0],self.shape[1]))),
                     row_names=self.row_names,
                     col_names=self.col_names,
                     isdiagonal=False)
docs: get an 2D instance of self with all zeros
  
          Returns
          -------
          Matrix : Matrix