From e610e41543fa1c0f4e9439da9f4737bd9051b602 Mon Sep 17 00:00:00 2001
From: kronbichler <kronbichler@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Mon, 6 May 2013 20:16:54 +0000
Subject: [PATCH] Add a test (that currently fails) showing that early success
 in Bicgstab solver is not handled correctly when large numbers are present

git-svn-id: https://svn.dealii.org/trunk@29466 0785d39b-7218-0410-832d-ea1e28bc413d
---
 tests/lac/bicgstab_large.cc          | 85 ++++++++++++++++++++++++++++
 tests/lac/bicgstab_large/cmp/generic |  8 +++
 2 files changed, 93 insertions(+)
 create mode 100644 tests/lac/bicgstab_large.cc
 create mode 100644 tests/lac/bicgstab_large/cmp/generic

diff --git a/tests/lac/bicgstab_large.cc b/tests/lac/bicgstab_large.cc
new file mode 100644
index 0000000000..13262582a0
--- /dev/null
+++ b/tests/lac/bicgstab_large.cc
@@ -0,0 +1,85 @@
+//----------------------------  bicgstab_large.cc  ---------------------------
+//    $Id$
+//    Version: $Name$ 
+//
+//    Copyright (C) 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.
+//
+//----------------------------  bicgstab_large.cc  ---------------------------
+
+// check that bicgstab does not exit early when very large matrices are used
+
+#include "../tests.h"
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+#include <iomanip>
+#include "testmatrix.h"
+#include <deal.II/base/logstream.h>
+#include <deal.II/lac/sparse_matrix.h>
+#include <deal.II/lac/solver_bicgstab.h>
+#include <deal.II/lac/vector.h>
+#include <deal.II/lac/precondition.h>
+
+
+int main()
+{
+  std::ofstream logfile("bicgstab_large/output");
+  deallog << std::setprecision(4);
+  deallog.attach(logfile);
+  deallog.depth_console(0);
+  deallog.threshold_double(1.e-10);
+  
+  SparsityPattern sparsity_pattern(4,4);
+  sparsity_pattern.compress();
+  
+  SparseMatrix<double> M(sparsity_pattern);
+  M.diag_element(0) = 1;
+  M.diag_element(1) = 10;
+  M.diag_element(2) = 11;
+  M.diag_element(3) = 42;
+
+  Vector<double> rhs(4);
+  rhs(0) = rhs(2) = 0;
+  rhs(1) = rhs(3) = 0.0975;
+
+  Vector<double> solution (4);
+
+  {
+    SolverControl control(100, 1.e-3);
+    SolverBicgstab<> bicgstab(control);
+    bicgstab.solve (M, solution, rhs, PreconditionIdentity());
+  }
+
+  for (unsigned int i=0; i<4; ++i)
+    deallog << solution(i) << std::endl;
+
+  Vector<double> res (4);
+  M.residual (res, solution, rhs);
+  deallog << "residual=" << res.l2_norm()
+	  << std::endl;
+
+  // now set up the same problem but with matrix entries scaled by 1e10 and
+  // solver tolerance scaled by 1e10. should get the same solution
+  SparseMatrix<double> M1 (sparsity_pattern);
+  M1.add(1e10,M);
+  rhs *= 1e10;
+
+  {
+    SolverControl control(100, 1.e7);
+    SolverBicgstab<> bicgstab(control);
+    bicgstab.solve (M1, solution, rhs, PreconditionIdentity());
+  }
+
+  for (unsigned int i=0; i<4; ++i)
+    deallog << solution(i) << std::endl;
+
+  M1.residual (res, solution, rhs);
+  deallog << "residual=" << res.l2_norm()
+	  << std::endl;
+}
+
diff --git a/tests/lac/bicgstab_large/cmp/generic b/tests/lac/bicgstab_large/cmp/generic
new file mode 100644
index 0000000000..c20f61f9cc
--- /dev/null
+++ b/tests/lac/bicgstab_large/cmp/generic
@@ -0,0 +1,8 @@
+
+DEAL:Bicgstab::Starting value 0.1379
+DEAL:Bicgstab::Convergence step 1 value 0
+DEAL::0
+DEAL::0.009242
+DEAL::0
+DEAL::0.009242
+DEAL::residual=0
-- 
2.39.5