// Ceres Solver - A fast non-linear least squares minimizer

// Copyright 2015 Google Inc. All rights reserved.

// http://ceres-solver.org/

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// Author: sameeragarwal@google.com (Sameer Agarwal)

#ifndef CERES_INTERNAL_COVARIANCE_IMPL_H_

#define CERES_INTERNAL_COVARIANCE_IMPL_H_

#include <map>

#include <set>

#include <utility>

#include <vector>

#include "ceres/covariance.h"

#include "ceres/internal/scoped_ptr.h"

#include "ceres/problem_impl.h"

#include "ceres/suitesparse.h"

namespace ceres {

namespace internal {

class CompressedRowSparseMatrix;

class CovarianceImpl {

 public:

  explicit CovarianceImpl(const Covariance::Options& options);

  ~CovarianceImpl();

  bool Compute(

      const std::vector

                                  const double*> >& covariance_blocks,

      ProblemImpl* problem);

  bool Compute(

      const std::vector<const double*>& parameter_blocks,

      ProblemImpl* problem);

  bool GetCovarianceBlockInTangentOrAmbientSpace(

      const double* parameter_block1,

      const double* parameter_block2,

      bool lift_covariance_to_ambient_space,

      double* covariance_block) const;

  bool GetCovarianceMatrixInTangentOrAmbientSpace(

      const std::vector<const double*>& parameters,

      bool lift_covariance_to_ambient_space,

      double *covariance_matrix) const;

  bool ComputeCovarianceSparsity(

      const std::vector

                                  const double*> >& covariance_blocks,

      ProblemImpl* problem);

  bool ComputeCovarianceValues();

  bool ComputeCovarianceValuesUsingDenseSVD();

  bool ComputeCovarianceValuesUsingSuiteSparseQR();

  bool ComputeCovarianceValuesUsingEigenSparseQR();

  const CompressedRowSparseMatrix* covariance_matrix() const {

    return covariance_matrix_.get();

  }

 private:

  ProblemImpl* problem_;

  Covariance::Options options_;

  Problem::EvaluateOptions evaluate_options_;

  bool is_computed_;

  bool is_valid_;

  std::map<const double*, int> parameter_block_to_row_index_;

  std::set<const double*> constant_parameter_blocks_;

  scoped_ptr<CompressedRowSparseMatrix> covariance_matrix_;

};

}  // namespace internal

}  // namespace ceres

#endif  // CERES_INTERNAL_COVARIANCE_IMPL_H_