code: def eval_objfn(self):
          r
  
          obj = np.linalg.norm((self.wl1 * self.obfn_g0var()).ravel(), 1)
          cns = np.linalg.norm(sl.proj_l2ball(
              self.obfn_g1var(), self.S, self.epsilon, axes=0) -
              self.obfn_g1var())
          return (obj, cns)
docs: r"""Compute components of objective function as well as total
          contribution to objective function.  The objective function is
          :math:`\| \mathbf{x} \|_1` and the constraint violation
          measure is :math:`P(\mathbf{x}) - \mathbf{x}` where
          :math:`P(\mathbf{x})` is the projection into the constraint
          set.