From 749a595a0eed501602c9f7316e1c1a5839dc7645 Mon Sep 17 00:00:00 2001
From: bangerth <bangerth@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Tue, 21 May 2013 12:30:22 +0000
Subject: [PATCH] Add a test.

git-svn-id: https://svn.dealii.org/trunk@29532 0785d39b-7218-0410-832d-ea1e28bc413d
---
 tests/mpi/petsc_condense_02.cc                | 170 ++++++++++++++++++
 .../mpi/petsc_condense_02/ncpu_1/cmp/generic  |   2 +
 .../mpi/petsc_condense_02/ncpu_10/cmp/generic |   2 +
 .../mpi/petsc_condense_02/ncpu_2/cmp/generic  |   2 +
 .../mpi/petsc_condense_02/ncpu_4/cmp/generic  |   2 +
 5 files changed, 178 insertions(+)
 create mode 100644 tests/mpi/petsc_condense_02.cc
 create mode 100644 tests/mpi/petsc_condense_02/ncpu_1/cmp/generic
 create mode 100644 tests/mpi/petsc_condense_02/ncpu_10/cmp/generic
 create mode 100644 tests/mpi/petsc_condense_02/ncpu_2/cmp/generic
 create mode 100644 tests/mpi/petsc_condense_02/ncpu_4/cmp/generic

diff --git a/tests/mpi/petsc_condense_02.cc b/tests/mpi/petsc_condense_02.cc
new file mode 100644
index 0000000000..4499b9b583
--- /dev/null
+++ b/tests/mpi/petsc_condense_02.cc
@@ -0,0 +1,170 @@
+//---------------------------------------------------------------------------
+//    $Id$
+//    Version: $Name$
+//
+//    Copyright (C) 2009, 2010, 2012, 2013 by the deal.II authors
+//
+//    This file is subject to QPL and may not be  distributed
+//    without copyright and license information. Please refer
+//    to the file deal.II/doc/license.html for the  text  and
+//    further information on this license.
+//
+//---------------------------------------------------------------------------
+
+
+// check ConstraintMatrix.distribute() for a petsc vector
+//
+// we do this by creating a vector where each processor has 100
+// elements but no ghost elements. then we add constraints on each
+// processor that constrain elements within each processor's local
+// range to ones outside. these have to be added on all
+// processors. then call distribute() and verify that the result is
+// true.
+//
+// we use constraints of the form x_i = x_j with sequentially growing
+// x_j's so that we can verify the correctness analytically
+//
+// compared to the _01 test, here the ConstraintMatrix object acts on an index
+// set that only includes the locally owned vector elements, without any
+// overlap. this verifies that we really only need to know about the *sources*
+// of constraints locally, not the *targets*.
+
+
+#include "../tests.h"
+#include <deal.II/base/logstream.h>
+#include <deal.II/lac/petsc_parallel_vector.h>
+#include <deal.II/lac/constraint_matrix.h>
+
+#include <fstream>
+#include <sstream>
+
+
+
+void test()
+{
+  const unsigned int myid = Utilities::MPI::this_mpi_process (MPI_COMM_WORLD);
+  const unsigned int n_processes = Utilities::MPI::n_mpi_processes (MPI_COMM_WORLD);
+
+  // create a vector that consists of elements indexed from 0 to n
+  PETScWrappers::MPI::Vector vec (MPI_COMM_WORLD, 100 * n_processes, 100);
+  Assert (vec.local_size() == 100, ExcInternalError());
+  Assert (vec.local_range().first == 100*myid, ExcInternalError());
+  Assert (vec.local_range().second == 100*myid+100, ExcInternalError());
+  for (unsigned int i=vec.local_range().first; i<vec.local_range().second; ++i)
+    vec(i) = i;
+  vec.compress();
+
+  // verify correctness so far
+  {
+    double exact_l1 = 0;
+    for (unsigned int i=0; i<vec.size(); ++i)
+      exact_l1 += i;
+    Assert (vec.l1_norm() == exact_l1, ExcInternalError());
+  }
+
+
+  // create a ConstraintMatrix with a range that only includes locally active
+  // DoFs
+  IndexSet locally_relevant_range (vec.size());
+  locally_relevant_range.add_range (100*myid,
+				    100*myid+100);
+  ConstraintMatrix cm (locally_relevant_range);
+
+  // add constraints that constrain an element in the middle of the
+  // local range of each processor against an element outside, both in
+  // the ghost range before and after
+  //
+  // note that we tell each processor about all constraints, but most
+  // of them will throw away this information since it is not for a
+  // DoF inside the locally relevant range
+  for (unsigned int p=0; p<n_processes; ++p)
+    {
+      if ((p != 0) && locally_relevant_range.is_element (p*100+10))
+	{
+	  cm.add_line (p*100+10);
+	  cm.add_entry (p*100+10,
+			p*100-25,
+			1);
+	}
+
+      if ((p != n_processes-1) && locally_relevant_range.is_element (p*100+90))
+	{
+	  cm.add_line (p*100+90);
+	  cm.add_entry (p*100+90,
+			p*100+105,
+			1);
+	}
+    }
+  cm.close ();
+
+  // now distribute these constraints
+  cm.distribute (vec);
+
+  // verify correctness
+  vec.compress ();
+
+  if (myid != 0)
+    Assert (vec(vec.local_range().first+10) == vec.local_range().first-25,
+	    ExcInternalError());
+
+  if (myid != n_processes-1)
+    Assert (vec(vec.local_range().first+90) == vec.local_range().first+105,
+	    ExcInternalError());
+
+  for (unsigned int i=vec.local_range().first; i<vec.local_range().second; ++i)
+    {
+      if ((i != vec.local_range().first+10)
+	  &&
+	  (i != vec.local_range().first+90))
+	{
+	  double val = vec(i);
+	  Assert (std::fabs(val - i) <= 1e-6, ExcInternalError());
+	}
+    }
+
+  {
+    double exact_l1 = 0;
+
+    // add up original values of vector entries
+    for (unsigned int i=0; i<vec.size(); ++i)
+      exact_l1 += i;
+
+    // but then correct for the constrained values
+    for (unsigned int p=0; p<n_processes; ++p)
+      {
+	if (p != 0)
+	  exact_l1 = exact_l1 - (p*100+10) + (p*100-25);
+	if (p != n_processes-1)
+	  exact_l1 = exact_l1 - (p*100+90) + (p*100+105);
+      }
+
+    Assert (vec.l1_norm() == exact_l1, ExcInternalError());
+
+    if (myid == 0)
+      deallog << "Norm = " << vec.l1_norm() << std::endl;
+  }
+}
+
+
+int main(int argc, char *argv[])
+{
+  Utilities::MPI::MPI_InitFinalize mpi_initialization(argc, argv, 1);
+
+  unsigned int myid = Utilities::MPI::this_mpi_process (MPI_COMM_WORLD);
+
+
+  deallog.push(Utilities::int_to_string(myid));
+
+  if (myid == 0)
+    {
+      std::ofstream logfile(output_file_for_mpi("petsc_condense_02").c_str());
+      deallog.attach(logfile);
+      deallog.depth_console(0);
+      deallog.threshold_double(1.e-10);
+
+      test();
+    }
+  else
+    test();
+
+}
diff --git a/tests/mpi/petsc_condense_02/ncpu_1/cmp/generic b/tests/mpi/petsc_condense_02/ncpu_1/cmp/generic
new file mode 100644
index 0000000000..2547450a42
--- /dev/null
+++ b/tests/mpi/petsc_condense_02/ncpu_1/cmp/generic
@@ -0,0 +1,2 @@
+
+DEAL:0::Norm = 4950.00
diff --git a/tests/mpi/petsc_condense_02/ncpu_10/cmp/generic b/tests/mpi/petsc_condense_02/ncpu_10/cmp/generic
new file mode 100644
index 0000000000..464154b458
--- /dev/null
+++ b/tests/mpi/petsc_condense_02/ncpu_10/cmp/generic
@@ -0,0 +1,2 @@
+
+DEAL:0::Norm = 499320.
diff --git a/tests/mpi/petsc_condense_02/ncpu_2/cmp/generic b/tests/mpi/petsc_condense_02/ncpu_2/cmp/generic
new file mode 100644
index 0000000000..a5749c49bf
--- /dev/null
+++ b/tests/mpi/petsc_condense_02/ncpu_2/cmp/generic
@@ -0,0 +1,2 @@
+
+DEAL:0::Norm = 19880.0
diff --git a/tests/mpi/petsc_condense_02/ncpu_4/cmp/generic b/tests/mpi/petsc_condense_02/ncpu_4/cmp/generic
new file mode 100644
index 0000000000..848c4e7ef5
--- /dev/null
+++ b/tests/mpi/petsc_condense_02/ncpu_4/cmp/generic
@@ -0,0 +1,2 @@
+
+DEAL:0::Norm = 79740.0
-- 
2.39.5