Add a test.

diff --git a/tests/petsc/iterate_parallel_01.cc b/tests/petsc/iterate_parallel_01.cc
new file mode 100644 (file)
index 0000000..a1dd40d
--- /dev/null
+++ b/tests/petsc/iterate_parallel_01.cc
@@ -0,0 +1,94 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2018 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.
+//
+// ---------------------------------------------------------------------
+
+
+// Check that we can iterate over the elements of a parallel
+// PETSc matrix. This was made more difficult than necessary
+// because calling PETScWrappers::MatrixBase::end(row) may
+// access a row that is not actually stored on the current
+// processor, but is also not the one-past-the-end row that
+// we internally tested.
+//
+// The test is lightly adapted from one provided by Feimi Yu
+
+#include "../tests.h"
+#include <deal.II/lac/dynamic_sparsity_pattern.h>
+#include <deal.II/lac/petsc_parallel_sparse_matrix.h>
+#include <deal.II/lac/petsc_precondition.h>
+#include <deal.II/base/index_set.h>
+#include <iostream>
+#include <vector>
+
+void test ()
+{
+  unsigned int myid = Utilities::MPI::this_mpi_process (MPI_COMM_WORLD);
+  unsigned int numproc = Utilities::MPI::n_mpi_processes (MPI_COMM_WORLD);
+
+  deallog << numproc << std::endl;
+
+  // set up disjoint index sets and some overlapping ghosted elements
+  IndexSet local_active(numproc*2);
+  local_active.add_range(myid*2,myid*2+2);
+  IndexSet local_relevant= local_active;
+  local_relevant.add_range(0,1);
+
+  DynamicSparsityPattern csp (local_relevant);
+
+  for (unsigned int i=0; i<2*numproc; ++i)
+    if (local_relevant.is_element(i))
+      csp.add(i,i);
+
+  csp.add(0,1);
+
+
+  PETScWrappers::MPI::SparseMatrix mat;
+  mat.reinit (local_active, local_active, csp, MPI_COMM_WORLD);
+
+  Assert(mat.n()==numproc*2, ExcInternalError());
+  Assert(mat.m()==numproc*2, ExcInternalError());
+
+  // set local values
+  mat.set(myid*2,myid*2, 1.0+myid*2.0);
+  mat.set(myid*2+1,myid*2+1, 2.0+myid*2.0);
+
+  mat.compress(VectorOperation::insert);
+
+  //////////////////////////////////////////////
+  /////This is a test for the local matrix iterator
+  //////////////////////////////////////////////
+  unsigned int start_row = mat.local_range().first;
+  unsigned int end_row = mat.local_range().second;
+  for (auto r = start_row; r < end_row; ++r)
+    {
+      for (auto itr = mat.begin(r); itr != mat.end(r); ++itr)
+        {
+          deallog << itr->row() << ' ' << itr->column() << ' ' << itr->value()
+                  << std::endl;
+        }
+    }
+  /////////////////////////////////////////////
+
+  if (myid==0)
+    deallog << "OK" << std::endl;
+}
+
+
+int main (int argc, char **argv)
+{
+  Utilities::MPI::MPI_InitFinalize mpi_initialization (argc, argv, 1);
+  MPILogInitAll log;
+
+  test ();
+}

diff --git a/tests/petsc/iterate_parallel_01.mpirun=2.output b/tests/petsc/iterate_parallel_01.mpirun=2.output
new file mode 100644 (file)
index 0000000..b551254
--- /dev/null
+++ b/tests/petsc/iterate_parallel_01.mpirun=2.output
@@ -0,0 +1,11 @@
+
+DEAL:0::2
+DEAL:0::0 0 1.00000
+DEAL:0::0 1 0.00000
+DEAL:0::1 1 2.00000
+DEAL:0::OK
+
+DEAL:1::2
+DEAL:1::2 2 3.00000
+DEAL:1::3 3 4.00000
+