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diff --git a/internal/ceres/symmetric_linear_solver_test.cc b/internal/ceres/symmetric_linear_solver_test.cc
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+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
+// http://code.google.com/p/ceres-solver/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+//   this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright notice,
+//   this list of conditions and the following disclaimer in the documentation
+//   and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors may be
+//   used to endorse or promote products derived from this software without
+//   specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: fredp@google.com (Fred Pighin)
+//
+// Tests for linear solvers that solve symmetric linear systems. Some
+// of this code is inhertited from Fred Pighin's code for testing the
+// old Conjugate Gradients solver.
+//
+// TODO(sameeragarwal): More comprehensive testing with larger and
+// more badly conditioned problem.
+
+#include "gtest/gtest.h"
+#include "ceres/conjugate_gradients_solver.h"
+#include "ceres/linear_solver.h"
+#include "ceres/triplet_sparse_matrix.h"
+#include "ceres/internal/eigen.h"
+#include "ceres/internal/scoped_ptr.h"
+#include "ceres/types.h"
+
+namespace ceres {
+namespace internal {
+
+TEST(ConjugateGradientTest, Solves3x3IdentitySystem) {
+  double diagonal[] = { 1.0, 1.0, 1.0 };
+  scoped_ptr<TripletSparseMatrix>
+      A(TripletSparseMatrix::CreateSparseDiagonalMatrix(diagonal, 3));
+  Vector b(3);
+  Vector x(3);
+
+  b(0) = 1.0;
+  b(1) = 2.0;
+  b(2) = 3.0;
+
+  x(0) = 1;
+  x(1) = 1;
+  x(2) = 1;
+
+  LinearSolver::Options options;
+  options.max_num_iterations = 10;
+
+  LinearSolver::PerSolveOptions per_solve_options;
+  per_solve_options.r_tolerance = 1e-9;
+
+  ConjugateGradientsSolver solver(options);
+  LinearSolver::Summary summary =
+      solver.Solve(A.get(), b.data(), per_solve_options, x.data());
+
+  EXPECT_EQ(summary.termination_type, TOLERANCE);
+  ASSERT_EQ(summary.num_iterations, 1);
+
+  ASSERT_DOUBLE_EQ(1, x(0));
+  ASSERT_DOUBLE_EQ(2, x(1));
+  ASSERT_DOUBLE_EQ(3, x(2));
+}
+
+
+TEST(ConjuateGradientTest, Solves3x3SymmetricSystem) {
+  scoped_ptr<TripletSparseMatrix> A(new TripletSparseMatrix(3, 3, 9));
+  Vector b(3);
+  Vector x(3);
+
+  //      | 2  -1  0|
+  //  A = |-1   2 -1| is symmetric positive definite.
+  //      | 0  -1  2|
+  int* Ai = A->mutable_rows();
+  int* Aj = A->mutable_cols();
+  double* Ax = A->mutable_values();
+  int counter = 0;
+  for (int i = 0; i < 3; ++i) {
+    for (int j = 0; j < 3; ++j) {
+      Ai[counter] = i;
+      Aj[counter] = j;
+      ++counter;
+    }
+  }
+  Ax[0] = 2.;
+  Ax[1] = -1.;
+  Ax[2] = 0;
+  Ax[3] = -1.;
+  Ax[4] = 2;
+  Ax[5] = -1;
+  Ax[6] = 0;
+  Ax[7] = -1;
+  Ax[8] = 2;
+  A->set_num_nonzeros(9);
+
+  b(0) = -1;
+  b(1) = 0;
+  b(2) = 3;
+
+  x(0) = 1;
+  x(1) = 1;
+  x(2) = 1;
+
+  LinearSolver::Options options;
+  options.max_num_iterations = 10;
+
+  LinearSolver::PerSolveOptions per_solve_options;
+  per_solve_options.r_tolerance = 1e-9;
+
+  ConjugateGradientsSolver solver(options);
+  LinearSolver::Summary summary =
+      solver.Solve(A.get(), b.data(), per_solve_options, x.data());
+
+  EXPECT_EQ(summary.termination_type, TOLERANCE);
+
+  ASSERT_DOUBLE_EQ(0, x(0));
+  ASSERT_DOUBLE_EQ(1, x(1));
+  ASSERT_DOUBLE_EQ(2, x(2));
+}
+
+}  // namespace internal
+}  // namespace ceres