From d38becaa81c758785612dbd65b932f8a27647c6c Mon Sep 17 00:00:00 2001
From: Matthias Maier <tamiko@43-1.org>
Date: Sun, 2 Jul 2017 12:20:13 -0500
Subject: [PATCH] Port arpack/step-36_parpack_mf to use inverse_operator

---
 tests/arpack/step-36_parpack_mf.cc | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/tests/arpack/step-36_parpack_mf.cc b/tests/arpack/step-36_parpack_mf.cc
index 3405ee3e8b..031cdca388 100644
--- a/tests/arpack/step-36_parpack_mf.cc
+++ b/tests/arpack/step-36_parpack_mf.cc
@@ -36,7 +36,7 @@
 #include <deal.II/fe/fe_tools.h>
 #include <deal.II/grid/grid_generator.h>
 #include <deal.II/matrix_free/operators.h>
-#include <deal.II/lac/iterative_inverse.h>
+#include <deal.II/lac/linear_operator.h>
 #include <deal.II/lac/precondition.h>
 #include <deal.II/numerics/vector_tools.h>
 
@@ -121,25 +121,26 @@ void test ()
     SolverControl solver_control     (dof_handler.n_dofs(), 1e-9,/*log_history*/false,/*log_results*/false);
     SolverControl solver_control_lin (dof_handler.n_dofs(), 1e-10,/*log_history*/false,/*log_results*/false);
 
+    // set up iterative inverse
+    static ReductionControl inner_control_c(dof_handler.n_dofs(), 0.0, 1.e-13);
 
+    typedef LinearAlgebra::distributed::Vector<double> VectorType;
+    SolverCG<VectorType> solver_c(inner_control_c);
     PreconditionIdentity preconditioner;
-    IterativeInverse<LinearAlgebra::distributed::Vector<double> > shift_and_invert;
-    shift_and_invert.initialize(laplace,preconditioner);
-    shift_and_invert.solver.select("cg");
-    static ReductionControl inner_control_c(dof_handler.n_dofs(), 0.0, 1.e-13);
-    shift_and_invert.solver.set_control(inner_control_c);
+    const auto shift_and_invert =
+      inverse_operator(linear_operator<VectorType>(laplace),
+                       solver_c,
+                       preconditioner);
 
     const unsigned int num_arnoldi_vectors = 2*eigenvalues.size() + 2;
-
     PArpackSolver<LinearAlgebra::distributed::Vector<double> >::AdditionalData
     additional_data(num_arnoldi_vectors,
                     PArpackSolver<LinearAlgebra::distributed::Vector<double> >::largest_magnitude,
                     true);
 
-    PArpackSolver<LinearAlgebra::distributed::Vector<double> > eigensolver
-    (solver_control,
-     mpi_communicator,
-     additional_data);
+    PArpackSolver<LinearAlgebra::distributed::Vector<double>> eigensolver(
+      solver_control, mpi_communicator, additional_data);
+
     eigensolver.reinit(eigenfunctions[0]);
     // make sure initial vector is orthogonal to the space due to constraints
     {
-- 
2.39.5