226 lines
8.4 KiB
C
226 lines
8.4 KiB
C
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// Ceres Solver - A fast non-linear least squares minimizer
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// Copyright 2015 Google Inc. All rights reserved.
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// http://ceres-solver.org/
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are met:
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//
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// * Redistributions of source code must retain the above copyright notice,
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// this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above copyright notice,
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// this list of conditions and the following disclaimer in the documentation
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// and/or other materials provided with the distribution.
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// * Neither the name of Google Inc. nor the names of its contributors may be
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// used to endorse or promote products derived from this software without
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// specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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// POSSIBILITY OF SUCH DAMAGE.
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//
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// Author: sameeragarwal@google.com (Sameer Agarwal)
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//
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// When an iteration callback is specified, Ceres calls the callback
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// after each minimizer step (if the minimizer has not converged) and
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// passes it an IterationSummary object, defined below.
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#ifndef CERES_PUBLIC_ITERATION_CALLBACK_H_
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#define CERES_PUBLIC_ITERATION_CALLBACK_H_
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#include "ceres/types.h"
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#include "ceres/internal/disable_warnings.h"
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namespace ceres {
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// This struct describes the state of the optimizer after each
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// iteration of the minimization.
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struct CERES_EXPORT IterationSummary {
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IterationSummary()
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: iteration(0),
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step_is_valid(false),
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step_is_nonmonotonic(false),
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step_is_successful(false),
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cost(0.0),
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cost_change(0.0),
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gradient_max_norm(0.0),
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gradient_norm(0.0),
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step_norm(0.0),
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eta(0.0),
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step_size(0.0),
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line_search_function_evaluations(0),
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line_search_gradient_evaluations(0),
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line_search_iterations(0),
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linear_solver_iterations(0),
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iteration_time_in_seconds(0.0),
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step_solver_time_in_seconds(0.0),
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cumulative_time_in_seconds(0.0) {}
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// Current iteration number.
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int32 iteration;
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// Step was numerically valid, i.e., all values are finite and the
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// step reduces the value of the linearized model.
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//
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// Note: step_is_valid is false when iteration = 0.
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bool step_is_valid;
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// Step did not reduce the value of the objective function
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// sufficiently, but it was accepted because of the relaxed
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// acceptance criterion used by the non-monotonic trust region
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// algorithm.
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//
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// Note: step_is_nonmonotonic is false when iteration = 0;
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bool step_is_nonmonotonic;
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// Whether or not the minimizer accepted this step or not. If the
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// ordinary trust region algorithm is used, this means that the
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// relative reduction in the objective function value was greater
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// than Solver::Options::min_relative_decrease. However, if the
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// non-monotonic trust region algorithm is used
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// (Solver::Options:use_nonmonotonic_steps = true), then even if the
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// relative decrease is not sufficient, the algorithm may accept the
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// step and the step is declared successful.
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//
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// Note: step_is_successful is false when iteration = 0.
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bool step_is_successful;
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// Value of the objective function.
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double cost;
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// Change in the value of the objective function in this
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// iteration. This can be positive or negative.
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double cost_change;
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// Infinity norm of the gradient vector.
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double gradient_max_norm;
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// 2-norm of the gradient vector.
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double gradient_norm;
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// 2-norm of the size of the step computed by the optimization
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// algorithm.
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double step_norm;
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// For trust region algorithms, the ratio of the actual change in
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// cost and the change in the cost of the linearized approximation.
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double relative_decrease;
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// Size of the trust region at the end of the current iteration. For
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// the Levenberg-Marquardt algorithm, the regularization parameter
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// mu = 1.0 / trust_region_radius.
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double trust_region_radius;
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// For the inexact step Levenberg-Marquardt algorithm, this is the
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// relative accuracy with which the Newton(LM) step is solved. This
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// number affects only the iterative solvers capable of solving
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// linear systems inexactly. Factorization-based exact solvers
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// ignore it.
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double eta;
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// Step sized computed by the line search algorithm.
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double step_size;
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// Number of function value evaluations used by the line search algorithm.
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int line_search_function_evaluations;
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// Number of function gradient evaluations used by the line search algorithm.
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int line_search_gradient_evaluations;
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// Number of iterations taken by the line search algorithm.
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int line_search_iterations;
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// Number of iterations taken by the linear solver to solve for the
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// Newton step.
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int linear_solver_iterations;
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// All times reported below are wall times.
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// Time (in seconds) spent inside the minimizer loop in the current
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// iteration.
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double iteration_time_in_seconds;
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// Time (in seconds) spent inside the trust region step solver.
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double step_solver_time_in_seconds;
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// Time (in seconds) since the user called Solve().
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double cumulative_time_in_seconds;
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};
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// Interface for specifying callbacks that are executed at the end of
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// each iteration of the Minimizer. The solver uses the return value
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// of operator() to decide whether to continue solving or to
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// terminate. The user can return three values.
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//
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// SOLVER_ABORT indicates that the callback detected an abnormal
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// situation. The solver returns without updating the parameter blocks
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// (unless Solver::Options::update_state_every_iteration is set
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// true). Solver returns with Solver::Summary::termination_type set to
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// USER_ABORT.
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//
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// SOLVER_TERMINATE_SUCCESSFULLY indicates that there is no need to
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// optimize anymore (some user specified termination criterion has
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// been met). Solver returns with Solver::Summary::termination_type
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// set to USER_SUCCESS.
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//
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// SOLVER_CONTINUE indicates that the solver should continue
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// optimizing.
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//
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// For example, the following Callback is used internally by Ceres to
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// log the progress of the optimization.
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//
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// Callback for logging the state of the minimizer to STDERR or STDOUT
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// depending on the user's preferences and logging level.
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//
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// class LoggingCallback : public IterationCallback {
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// public:
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// explicit LoggingCallback(bool log_to_stdout)
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// : log_to_stdout_(log_to_stdout) {}
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//
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// ~LoggingCallback() {}
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//
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// CallbackReturnType operator()(const IterationSummary& summary) {
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// const char* kReportRowFormat =
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// "% 4d: f:% 8e d:% 3.2e g:% 3.2e h:% 3.2e "
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// "rho:% 3.2e mu:% 3.2e eta:% 3.2e li:% 3d";
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// string output = StringPrintf(kReportRowFormat,
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// summary.iteration,
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// summary.cost,
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// summary.cost_change,
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// summary.gradient_max_norm,
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// summary.step_norm,
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// summary.relative_decrease,
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// summary.trust_region_radius,
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// summary.eta,
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// summary.linear_solver_iterations);
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// if (log_to_stdout_) {
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// cout << output << endl;
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// } else {
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// VLOG(1) << output;
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// }
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// return SOLVER_CONTINUE;
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// }
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//
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// private:
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// const bool log_to_stdout_;
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// };
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//
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class CERES_EXPORT IterationCallback {
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public:
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virtual ~IterationCallback() {}
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virtual CallbackReturnType operator()(const IterationSummary& summary) = 0;
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};
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} // namespace ceres
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#include "ceres/internal/reenable_warnings.h"
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#endif // CERES_PUBLIC_ITERATION_CALLBACK_H_
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