Squashed 'third_party/ceres/' content from commit e51e9b4

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diff --git a/internal/ceres/sparse_cholesky.cc b/internal/ceres/sparse_cholesky.cc
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+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2017 Google Inc. All rights reserved.
+// http://ceres-solver.org/
+//
+// 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/sparse_cholesky.h"
+
+#include "ceres/accelerate_sparse.h"
+#include "ceres/cxsparse.h"
+#include "ceres/eigensparse.h"
+#include "ceres/float_cxsparse.h"
+#include "ceres/float_suitesparse.h"
+#include "ceres/iterative_refiner.h"
+#include "ceres/suitesparse.h"
+
+namespace ceres {
+namespace internal {
+
+std::unique_ptr<SparseCholesky> SparseCholesky::Create(
+    const LinearSolver::Options& options) {
+  const OrderingType ordering_type = options.use_postordering ? AMD : NATURAL;
+  std::unique_ptr<SparseCholesky> sparse_cholesky;
+
+  switch (options.sparse_linear_algebra_library_type) {
+    case SUITE_SPARSE:
+#ifndef CERES_NO_SUITESPARSE
+      if (options.use_mixed_precision_solves) {
+        sparse_cholesky = FloatSuiteSparseCholesky::Create(ordering_type);
+      } else {
+        sparse_cholesky = SuiteSparseCholesky::Create(ordering_type);
+      }
+      break;
+#else
+      LOG(FATAL) << "Ceres was compiled without support for SuiteSparse.";
+#endif
+
+    case EIGEN_SPARSE:
+#ifdef CERES_USE_EIGEN_SPARSE
+      if (options.use_mixed_precision_solves) {
+        sparse_cholesky = FloatEigenSparseCholesky::Create(ordering_type);
+      } else {
+        sparse_cholesky = EigenSparseCholesky::Create(ordering_type);
+      }
+      break;
+#else
+      LOG(FATAL) << "Ceres was compiled without support for "
+                 << "Eigen's sparse Cholesky factorization routines.";
+#endif
+
+    case CX_SPARSE:
+#ifndef CERES_NO_CXSPARSE
+      if (options.use_mixed_precision_solves) {
+        sparse_cholesky = FloatCXSparseCholesky::Create(ordering_type);
+      } else {
+        sparse_cholesky = CXSparseCholesky::Create(ordering_type);
+      }
+      break;
+#else
+      LOG(FATAL) << "Ceres was compiled without support for CXSparse.";
+#endif
+
+    case ACCELERATE_SPARSE:
+#ifndef CERES_NO_ACCELERATE_SPARSE
+      if (options.use_mixed_precision_solves) {
+        sparse_cholesky = AppleAccelerateCholesky<float>::Create(ordering_type);
+      } else {
+        sparse_cholesky = AppleAccelerateCholesky<double>::Create(ordering_type);
+      }
+      break;
+#else
+      LOG(FATAL) << "Ceres was compiled without support for Apple's Accelerate "
+                 << "framework solvers.";
+#endif
+
+    default:
+      LOG(FATAL) << "Unknown sparse linear algebra library type : "
+                 << SparseLinearAlgebraLibraryTypeToString(
+                        options.sparse_linear_algebra_library_type);
+  }
+
+  if (options.max_num_refinement_iterations > 0) {
+    std::unique_ptr<IterativeRefiner> refiner(
+        new IterativeRefiner(options.max_num_refinement_iterations));
+    sparse_cholesky = std::unique_ptr<SparseCholesky>(new RefinedSparseCholesky(
+        std::move(sparse_cholesky), std::move(refiner)));
+  }
+  return sparse_cholesky;
+}
+
+SparseCholesky::~SparseCholesky() {}
+
+LinearSolverTerminationType SparseCholesky::FactorAndSolve(
+    CompressedRowSparseMatrix* lhs,
+    const double* rhs,
+    double* solution,
+    std::string* message) {
+  LinearSolverTerminationType termination_type = Factorize(lhs, message);
+  if (termination_type == LINEAR_SOLVER_SUCCESS) {
+    termination_type = Solve(rhs, solution, message);
+  }
+  return termination_type;
+}
+
+CompressedRowSparseMatrix::StorageType StorageTypeForSparseLinearAlgebraLibrary(
+    SparseLinearAlgebraLibraryType sparse_linear_algebra_library_type) {
+  if (sparse_linear_algebra_library_type == SUITE_SPARSE) {
+    return CompressedRowSparseMatrix::UPPER_TRIANGULAR;
+  }
+  return CompressedRowSparseMatrix::LOWER_TRIANGULAR;
+}
+
+RefinedSparseCholesky::RefinedSparseCholesky(
+    std::unique_ptr<SparseCholesky> sparse_cholesky,
+    std::unique_ptr<IterativeRefiner> iterative_refiner)
+    : sparse_cholesky_(std::move(sparse_cholesky)),
+      iterative_refiner_(std::move(iterative_refiner)) {}
+
+RefinedSparseCholesky::~RefinedSparseCholesky() {}
+
+CompressedRowSparseMatrix::StorageType RefinedSparseCholesky::StorageType()
+    const {
+  return sparse_cholesky_->StorageType();
+}
+
+LinearSolverTerminationType RefinedSparseCholesky::Factorize(
+    CompressedRowSparseMatrix* lhs, std::string* message) {
+  lhs_ = lhs;
+  return sparse_cholesky_->Factorize(lhs, message);
+}
+
+LinearSolverTerminationType RefinedSparseCholesky::Solve(const double* rhs,
+                                                         double* solution,
+                                                         std::string* message) {
+  CHECK(lhs_ != nullptr);
+  auto termination_type = sparse_cholesky_->Solve(rhs, solution, message);
+  if (termination_type != LINEAR_SOLVER_SUCCESS) {
+    return termination_type;
+  }
+
+  iterative_refiner_->Refine(*lhs_, rhs, sparse_cholesky_.get(), solution);
+  return LINEAR_SOLVER_SUCCESS;
+}
+
+}  // namespace internal
+}  // namespace ceres