iter =   0, Function value 153.798, Residual: 132.652 
iter =   1, Function value 19.6011, Residual: 1.73945 
iter =   2, Function value 19.561, Residual: 0.0252086 
iter =   3, Function value 19.561, Residual: 2.02714e-05 
iter =   4, Function value 19.561, Residual: < 1.0e-6 
Tao Object: 1 MPI process
  type: nls
    Newton steps: 4
    BFGS steps: 0
    Gradient steps: 0
    nls ksp atol: 0
    nls ksp rtol: 4
    nls ksp ctol: 0
    nls ksp negc: 0
    nls ksp dtol: 0
    nls ksp iter: 0
    nls ksp othr: 0
  Objective function:
    TaoTerm Object: 1 MPI process
      type: sum
      solution vector space: N = 20
      parameter vector space: (optional) K = 130
      Sum of 3 terms: f_{data_}(A_0 x; [p_0]) + 0.1 f_{ridge_}(x; [p_1]) + 0.1 f_{lasso_}(A_2 x; [p_2])
      f_{data_}:
        TaoTerm Object: (data_) 1 MPI process
          type: quadratic
          solution vector space: N = 100
          parameter vector space: (optional) K = 100
          Mat Object: 1 MPI process
            type: diagonal
            rows=100, cols=100
              Vec Object: 1 MPI process
                type: seq
      A_0:
        Mat Object: 1 MPI process
          type: seqdense
          rows=100, cols=20
          total: nonzeros=2000, allocated nonzeros=2000
          total number of mallocs used during MatSetValues calls=0
      f_{ridge_}:
        TaoTerm Object: (ridge_) 1 MPI process
          type: halfl2squared
          solution vector space: N = 20
          parameter vector space: (optional) K = 20
      f_{lasso_}:
        TaoTerm Object: (lasso_) 1 MPI process
          type: l1
          solution vector space: N = 10
          parameter vector space: (optional) K = 10
          epsilon (tao_term_l1_epsilon): 0.1
      A_2:
        Mat Object: 1 MPI process
          type: seqdense
          rows=10, cols=20
          total: nonzeros=200, allocated nonzeros=200
          total number of mallocs used during MatSetValues calls=0
  TaoLineSearch Object: 1 MPI process
    type: more-thuente
    maximum function evaluations=30
    tolerances: ftol=0.0001, rtol=1e-10, gtol=0.9
    total number of function evaluations=0
    total number of gradient evaluations=0
    total number of function/gradient evaluations=1
    Termination reason: SUCCESS
  KSP Object: (tao_nls_) 1 MPI process
    type: stcg
    maximum iterations=10000, initial guess is zero
    tolerances: relative=1e-05, absolute=1e-50, divergence=10000.
    left preconditioning
    using UNPRECONDITIONED norm type for convergence test
  PC Object: (tao_nls_) 1 MPI process
    type: none
    linear system matrix, followed by the matrix used to construct the preconditioner:
    Mat Object: 1 MPI process
      type: shell
      rows=20, cols=20
    Mat Object: 1 MPI process
      type: shell
      rows=20, cols=20
  total KSP iterations: 44
  convergence tolerances: gatol=1e-08,   grtol=1e-08,   steptol=0.,   gttol=0.
  Residual in Function/Gradient:=1.03566e-10
  Objective value=19.561
  total number of iterations=4,                          (max: 50)
  total number of function evaluations=5,                  (max: unlimited)
  total number of function/gradient evaluations=5,      (max: unlimited)
  total number of Hessian evaluations=4
  Solution converged:    ||g(X)|| <= gatol
