From bd1c495aa1ff95c39bf3c8dab184be718c92a544 Mon Sep 17 00:00:00 2001
From: David Wells <wellsd2@rpi.edu>
Date: Sun, 17 Sep 2017 16:55:58 -0400
Subject: [PATCH] Add a test for copying SUNDIALS vectors.

---
 tests/sundials/copy_01.cc                     | 73 +++++++++++++++++++
 ...h_mpi=true.with_petsc=true.mpirun=4.output | 15 ++++
 2 files changed, 88 insertions(+)
 create mode 100644 tests/sundials/copy_01.cc
 create mode 100644 tests/sundials/copy_01.with_mpi=true.with_petsc=true.mpirun=4.output

diff --git a/tests/sundials/copy_01.cc b/tests/sundials/copy_01.cc
new file mode 100644
index 0000000000..11cb7a68ca
--- /dev/null
+++ b/tests/sundials/copy_01.cc
@@ -0,0 +1,73 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2017 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, redistribute
+// it, and/or modify it under the terms of the GNU Lesser General
+// Public License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE at
+// the top level of the deal.II distribution.
+//
+// ---------------------------------------------------------------------
+
+// Verify that we can correctly copy a PETSc vector to a parallel (non-PETSc)
+// SUNDIALS vector.
+
+#include "../tests.h"
+
+#include <deal.II/base/mpi.h>
+#include <deal.II/lac/petsc_parallel_vector.h>
+#include <deal.II/sundials/copy.h>
+
+#include <iostream>
+#include <vector>
+
+int main (int argc, char **argv)
+{
+  Utilities::MPI::MPI_InitFinalize mpi_initialization (argc, argv, 1);
+  MPILogInitAll log_all;
+
+  const unsigned int current_process = Utilities::MPI::this_mpi_process(MPI_COMM_WORLD);
+  const unsigned int n_processes = Utilities::MPI::n_mpi_processes(MPI_COMM_WORLD);
+
+  // give the zeroth process 1 dof, the first 2, etc
+  const types::global_dof_index n_local_dofs = 1 + current_process;
+  const types::global_dof_index begin_dof = (current_process*(current_process + 1))/2;
+  const types::global_dof_index end_dof = begin_dof + n_local_dofs;
+
+  const types::global_dof_index n_global_dofs = ((n_processes - 1)*(n_processes))/2
+                                                + n_processes;
+  IndexSet local_dofs(n_global_dofs);
+  local_dofs.add_range(begin_dof, end_dof);
+  local_dofs.compress();
+  AssertDimension(local_dofs.n_elements(), n_local_dofs);
+
+
+  PETScWrappers::MPI::Vector vec(local_dofs, MPI_COMM_WORLD);
+  for (const types::global_dof_index local_dof : local_dofs)
+    {
+      vec[local_dof] = 2*local_dof - current_process;
+    }
+  vec.compress(VectorOperation::insert);
+  const std::size_t n_dofs = vec.size();
+
+  N_Vector sundials_vector = N_VNew_Parallel(MPI_COMM_WORLD,
+                                             n_local_dofs,
+                                             n_dofs);
+  SUNDIALS::internal::copy(sundials_vector, vec);
+
+  PETScWrappers::MPI::Vector vec2(local_dofs, MPI_COMM_WORLD);
+  SUNDIALS::internal::copy(vec2, sundials_vector);
+
+  AssertThrow(vec2 == vec,
+              ExcMessage("The two PETSc vectors should be equal since they are "
+                         "copies (by means of an intermediate SUNDIALs vector)"));
+
+  deallog << "n_local_dofs: "
+          << n_local_dofs
+          << std::endl;
+  deallog << "OK" << std::endl;
+}
diff --git a/tests/sundials/copy_01.with_mpi=true.with_petsc=true.mpirun=4.output b/tests/sundials/copy_01.with_mpi=true.with_petsc=true.mpirun=4.output
new file mode 100644
index 0000000000..ea6a78c882
--- /dev/null
+++ b/tests/sundials/copy_01.with_mpi=true.with_petsc=true.mpirun=4.output
@@ -0,0 +1,15 @@
+
+DEAL:0::n_local_dofs: 1
+DEAL:0::OK
+
+DEAL:1::n_local_dofs: 2
+DEAL:1::OK
+
+
+DEAL:2::n_local_dofs: 3
+DEAL:2::OK
+
+
+DEAL:3::n_local_dofs: 4
+DEAL:3::OK
+
-- 
2.39.5