MYNT-EYE-S-SDK/3rdparty/ceres-solver-1.11.0/internal/ceres/cgnr_solver.cc
2019-01-03 16:25:18 +08:00

89 lines
3.4 KiB
C++

// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2015 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: keir@google.com (Keir Mierle)
#include "ceres/cgnr_solver.h"
#include "ceres/block_jacobi_preconditioner.h"
#include "ceres/cgnr_linear_operator.h"
#include "ceres/conjugate_gradients_solver.h"
#include "ceres/internal/eigen.h"
#include "ceres/linear_solver.h"
#include "ceres/wall_time.h"
#include "glog/logging.h"
namespace ceres {
namespace internal {
CgnrSolver::CgnrSolver(const LinearSolver::Options& options)
: options_(options),
preconditioner_(NULL) {
if (options_.preconditioner_type != JACOBI &&
options_.preconditioner_type != IDENTITY) {
LOG(FATAL) << "CGNR only supports IDENTITY and JACOBI preconditioners.";
}
}
LinearSolver::Summary CgnrSolver::SolveImpl(
BlockSparseMatrix* A,
const double* b,
const LinearSolver::PerSolveOptions& per_solve_options,
double* x) {
EventLogger event_logger("CgnrSolver::Solve");
// Form z = Atb.
Vector z(A->num_cols());
z.setZero();
A->LeftMultiply(b, z.data());
// Precondition if necessary.
LinearSolver::PerSolveOptions cg_per_solve_options = per_solve_options;
if (options_.preconditioner_type == JACOBI) {
if (preconditioner_.get() == NULL) {
preconditioner_.reset(new BlockJacobiPreconditioner(*A));
}
preconditioner_->Update(*A, per_solve_options.D);
cg_per_solve_options.preconditioner = preconditioner_.get();
}
// Solve (AtA + DtD)x = z (= Atb).
VectorRef(x, A->num_cols()).setZero();
CgnrLinearOperator lhs(*A, per_solve_options.D);
event_logger.AddEvent("Setup");
ConjugateGradientsSolver conjugate_gradient_solver(options_);
LinearSolver::Summary summary =
conjugate_gradient_solver.Solve(&lhs, z.data(), cg_per_solve_options, x);
event_logger.AddEvent("Solve");
return summary;
}
} // namespace internal
} // namespace ceres