Initial commit of Ceres Solver.
diff --git a/internal/ceres/evaluator.cc b/internal/ceres/evaluator.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: keir@google.com (Keir Mierle)
+
+#include <glog/logging.h>
+#include "ceres/evaluator.h"
+#include "ceres/block_evaluate_preparer.h"
+#include "ceres/block_jacobian_writer.h"
+#include "ceres/compressed_row_jacobian_writer.h"
+#include "ceres/scratch_evaluate_preparer.h"
+#include "ceres/dense_jacobian_writer.h"
+#include "ceres/program_evaluator.h"
+
+namespace ceres {
+namespace internal {
+
+Evaluator::~Evaluator() {}
+
+Evaluator* Evaluator::Create(const Evaluator::Options& options,
+                             Program* program,
+                             string* error) {
+  switch (options.linear_solver_type) {
+    case DENSE_QR:
+      return new ProgramEvaluator<ScratchEvaluatePreparer,
+                                  DenseJacobianWriter>(options,
+                                                       program);
+    case DENSE_SCHUR:
+    case SPARSE_SCHUR:
+    case ITERATIVE_SCHUR:
+      return new ProgramEvaluator<BlockEvaluatePreparer,
+                                  BlockJacobianWriter>(options,
+                                                       program);
+    case SPARSE_NORMAL_CHOLESKY:
+      return new ProgramEvaluator<ScratchEvaluatePreparer,
+                                  CompressedRowJacobianWriter>(options,
+                                                               program);
+    case CONJUGATE_GRADIENTS:
+      *error = "CONJUGATE_GRADIENTS is not supported as a linear "
+          "solver. If you want to use an iterative linear solver, "
+          "use ITERATIVE_SCHUR instead.";
+      return NULL;
+    default:
+      *error = "Invalid Linear Solver Type. Unable to create evaluator.";
+      return NULL;
+  }
+}
+
+}  // namespace internal
+}  // namespace ceres