Initial commit of Ceres Solver.
diff --git a/internal/ceres/normal_prior_test.cc b/internal/ceres/normal_prior_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: sameeragarwal@google.com (Sameer Agarwal)
+
+#include "ceres/normal_prior.h"
+
+#include <cstddef>
+
+#include "gtest/gtest.h"
+#include "ceres/internal/eigen.h"
+#include "ceres/random.h"
+
+namespace ceres {
+namespace internal {
+
+void RandomVector(Vector* v) {
+  for (int r = 0; r < v->rows(); ++r)
+    (*v)[r] = 2 * RandDouble() - 1;
+}
+
+void RandomMatrix(Matrix* m) {
+  for (int r = 0; r < m->rows(); ++r) {
+    for (int c = 0; c < m->cols(); ++c) {
+      (*m)(r, c) = 2 * RandDouble() - 1;
+    }
+  }
+}
+
+TEST(NormalPriorTest, ResidualAtRandomPosition) {
+  srand(5);
+
+  for (int num_rows = 1; num_rows < 5; ++num_rows) {
+    for (int num_cols = 1; num_cols < 5; ++num_cols) {
+      Vector b(num_cols);
+      RandomVector(&b);
+
+      Matrix A(num_rows, num_cols);
+      RandomMatrix(&A);
+
+      double * x = new double[num_cols];
+      for (int i = 0; i < num_cols; ++i)
+        x[i] = 2 * RandDouble() - 1;
+
+      double * jacobian = new double[num_rows * num_cols];
+      Vector residuals(num_rows);
+
+      NormalPrior prior(A, b);
+      prior.Evaluate(&x, residuals.data(), &jacobian);
+
+      // Compare the norm of the residual
+      double residual_diff_norm =
+          (residuals - A * (VectorRef(x, num_cols) - b)).squaredNorm();
+      EXPECT_NEAR(residual_diff_norm, 0, 1e-10);
+
+      // Compare the jacobians
+      MatrixRef J(jacobian, num_rows, num_cols);
+      double jacobian_diff_norm = (J - A).norm();
+      EXPECT_NEAR(jacobian_diff_norm, 0.0, 1e-10);
+
+      delete []x;
+      delete []jacobian;
+    }
+  }
+}
+
+TEST(NormalPriorTest, ResidualAtRandomPositionNullJacobians) {
+  srand(5);
+
+  for (int num_rows = 1; num_rows < 5; ++num_rows) {
+    for (int num_cols = 1; num_cols < 5; ++num_cols) {
+      Vector b(num_cols);
+      RandomVector(&b);
+
+      Matrix A(num_rows, num_cols);
+      RandomMatrix(&A);
+
+      double * x = new double[num_cols];
+      for (int i = 0; i < num_cols; ++i)
+        x[i] = 2 * RandDouble() - 1;
+
+      double* jacobians[1];
+      jacobians[0] = NULL;
+
+      Vector residuals(num_rows);
+
+      NormalPrior prior(A, b);
+      prior.Evaluate(&x, residuals.data(), jacobians);
+
+      // Compare the norm of the residual
+      double residual_diff_norm =
+          (residuals - A * (VectorRef(x, num_cols) - b)).squaredNorm();
+      EXPECT_NEAR(residual_diff_norm, 0, 1e-10);
+
+      prior.Evaluate(&x, residuals.data(), NULL);
+      // Compare the norm of the residual
+      residual_diff_norm =
+          (residuals - A * (VectorRef(x, num_cols) - b)).squaredNorm();
+      EXPECT_NEAR(residual_diff_norm, 0, 1e-10);
+
+
+      delete []x;
+    }
+  }
+}
+
+}  // namespace internal
+}  // namespace ceres