Initial commit of Ceres Solver.
diff --git a/internal/ceres/test_util.cc b/internal/ceres/test_util.cc
new file mode 100644
index 0000000..2bf4009
--- /dev/null
+++ b/internal/ceres/test_util.cc
@@ -0,0 +1,110 @@
+// 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: keir@google.com (Keir Mierle)
+//
+// Utility functions useful for testing.
+
+#include <cmath>
+#include <glog/logging.h>
+#include "gtest/gtest.h"
+#include "ceres/stringprintf.h"
+
+namespace ceres {
+namespace internal {
+
+bool ExpectClose(double x, double y, double max_abs_relative_difference) {
+ double absolute_difference = fabs(x - y);
+ double relative_difference = absolute_difference / std::max(fabs(x), fabs(y));
+ if (x == 0 || y == 0) {
+ // If x or y is exactly zero, then relative difference doesn't have any
+ // meaning. Take the absolute difference instead.
+ relative_difference = absolute_difference;
+ }
+ if (relative_difference > max_abs_relative_difference) {
+ VLOG(1) << StringPrintf("x=%17g y=%17g abs=%17g rel=%17g",
+ x, y, absolute_difference, relative_difference);
+ }
+
+ EXPECT_NEAR(relative_difference, 0.0, max_abs_relative_difference);
+ return relative_difference <= max_abs_relative_difference;
+}
+
+void ExpectArraysCloseUptoScale(int n,
+ const double* p,
+ const double* q,
+ double tol) {
+ CHECK_GT(n, 0);
+ CHECK(p);
+ CHECK(q);
+
+ double p_max = 0;
+ double q_max = 0;
+ int p_i = 0;
+ int q_i = 0;
+
+ for (int i = 0; i < n; ++i) {
+ if (std::abs(p[i]) > p_max) {
+ p_max = std::abs(p[i]);
+ p_i = i;
+ }
+ if (std::abs(q[i]) > q_max) {
+ q_max = std::abs(q[i]);
+ q_i = i;
+ }
+ }
+
+ // If both arrays are all zeros, they are equal up to scale, but
+ // for testing purposes, that's more likely to be an error than
+ // a desired result.
+ CHECK_NE(p_max, 0.0);
+ CHECK_NE(q_max, 0.0);
+
+ for (int i = 0; i < n; ++i) {
+ double p_norm = p[i] / p[p_i];
+ double q_norm = q[i] / q[q_i];
+
+ EXPECT_NEAR(p_norm, q_norm, tol) << "i=" << i;
+ }
+}
+
+void ExpectArraysClose(int n,
+ const double* p,
+ const double* q,
+ double tol) {
+ CHECK_GT(n, 0);
+ CHECK(p);
+ CHECK(q);
+
+ for (int i = 0; i < n; ++i) {
+ EXPECT_NEAR(p[i], q[i], tol) << "i=" << i;
+ }
+}
+
+} // namespace internal
+} // namespace ceres
