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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 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
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// 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)
#ifndef CERES_PUBLIC_GRADIENT_PROBLEM_H_
#define CERES_PUBLIC_GRADIENT_PROBLEM_H_
#include <memory>
#include "ceres/first_order_function.h"
#include "ceres/internal/disable_warnings.h"
#include "ceres/internal/export.h"
#include "ceres/local_parameterization.h"
#include "ceres/manifold.h"
namespace ceres {
class FirstOrderFunction;
// Instances of GradientProblem represent general non-linear
// optimization problems that must be solved using just the value of
// the objective function and its gradient.
// Unlike the Problem class, which can only be used to model non-linear least
// squares problems, instances of GradientProblem are not restricted in the form
// of the objective function.
//
// Structurally GradientProblem is a composition of a FirstOrderFunction and
// optionally a Manifold.
//
// The FirstOrderFunction is responsible for evaluating the cost and gradient of
// the objective function.
//
// The Manifold is responsible for going back and forth between the ambient
// space and the local tangent space. (See manifold.h for more details). When a
// Manifold is not provided, then the tangent space is assumed to coincide with
// the ambient Euclidean space that the gradient vector lives in.
//
// Example usage:
//
// The following demonstrate the problem construction for Rosenbrock's function
//
// f(x,y) = (1-x)^2 + 100(y - x^2)^2;
//
// class Rosenbrock : public ceres::FirstOrderFunction {
// public:
// virtual ~Rosenbrock() {}
//
// virtual bool Evaluate(const double* parameters,
// double* cost,
// double* gradient) const {
// const double x = parameters[0];
// const double y = parameters[1];
//
// cost[0] = (1.0 - x) * (1.0 - x) + 100.0 * (y - x * x) * (y - x * x);
// if (gradient != nullptr) {
// gradient[0] = -2.0 * (1.0 - x) - 200.0 * (y - x * x) * 2.0 * x;
// gradient[1] = 200.0 * (y - x * x);
// }
// return true;
// };
//
// virtual int NumParameters() const { return 2; };
// };
//
// ceres::GradientProblem problem(new Rosenbrock());
//
// NOTE: We are currently in the process of transitioning from
// LocalParameterization to Manifolds in the Ceres API. During this period,
// GradientProblem will support using both Manifold and LocalParameterization
// objects interchangably. For methods in the API affected by this change, see
// their documentation below.
class CERES_EXPORT GradientProblem {
public:
// Takes ownership of the function.
explicit GradientProblem(FirstOrderFunction* function);
// Takes ownership of the function and the parameterization.
//
// NOTE: This constructor is deprecated and will be removed in the next public
// release of Ceres Solver. Please move to using the Manifold based
// constructor.
CERES_DEPRECATED_WITH_MSG(
"LocalParameterizations are deprecated. Please use the constructor that "
"uses Manifold instead.")
GradientProblem(FirstOrderFunction* function,
LocalParameterization* parameterization);
// Takes ownership of the function and the manifold.
GradientProblem(FirstOrderFunction* function, Manifold* manifold);
int NumParameters() const;
// Dimension of the manifold (and its tangent space).
//
// During the transition from LocalParameterization to Manifold, this method
// reports the LocalSize of the LocalParameterization or the TangentSize of
// the Manifold object associated with this problem.
int NumTangentParameters() const;
// Dimension of the manifold (and its tangent space).
//
// NOTE: This method is deprecated and will be removed in the next public
// release of Ceres Solver. Please move to using NumTangentParameters()
// instead.
int NumLocalParameters() const { return NumTangentParameters(); }
// This call is not thread safe.
bool Evaluate(const double* parameters, double* cost, double* gradient) const;
bool Plus(const double* x, const double* delta, double* x_plus_delta) const;
const FirstOrderFunction* function() const { return function_.get(); }
FirstOrderFunction* mutable_function() { return function_.get(); }
// NOTE: During the transition from LocalParameterization to Manifold we need
// to support both The LocalParameterization and Manifold based constructors.
//
// When the user uses the LocalParameterization, internally the solver will
// wrap it in a ManifoldAdapter object and return it when manifold or
// mutable_manifold are called.
//
// As a result this method will return a non-nullptr result if a Manifold or a
// LocalParameterization was used when constructing the GradientProblem.
const Manifold* manifold() const { return manifold_.get(); }
Manifold* mutable_manifold() { return manifold_.get(); }
// If the problem is constructed without a LocalParameterization or with a
// Manifold this method will return a nullptr.
//
// NOTE: This method is deprecated and will be removed in the next public
// release of Ceres Solver.
CERES_DEPRECATED_WITH_MSG("Use Manifolds instead.")
const LocalParameterization* parameterization() const {
return parameterization_.get();
}
// If the problem is constructed without a LocalParameterization or with a
// Manifold this method will return a nullptr.
//
// NOTE: This method is deprecated and will be removed in the next public
// release of Ceres Solver.
CERES_DEPRECATED_WITH_MSG("Use Manifolds instead.")
LocalParameterization* mutable_parameterization() {
return parameterization_.get();
}
private:
std::unique_ptr<FirstOrderFunction> function_;
CERES_DEPRECATED_WITH_MSG("")
std::unique_ptr<LocalParameterization> parameterization_;
std::unique_ptr<Manifold> manifold_;
std::unique_ptr<double[]> scratch_;
};
} // namespace ceres
#include "ceres/internal/reenable_warnings.h"
#endif // CERES_PUBLIC_GRADIENT_PROBLEM_H_