1 // Ceres Solver - A fast non-linear least squares minimizer
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3 // http://code.google.com/p/ceres-solver/
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28 //
29 // Author: sameeragarwal@google.com (Sameer Agarwal)
30 //
31 // For generalized bi-partite Jacobian matrices that arise in
32 // Structure from Motion related problems, it is sometimes useful to
33 // have access to the two parts of the matrix as linear operators
34 // themselves. This class provides that functionality.
35 
36 #ifndef CERES_INTERNAL_PARTITIONED_MATRIX_VIEW_H_
37 #define CERES_INTERNAL_PARTITIONED_MATRIX_VIEW_H_
38 
39 #include <algorithm>
40 #include <cstring>
41 #include <vector>
42 
43 #include "ceres/block_structure.h"
44 #include "ceres/internal/eigen.h"
45 #include "ceres/linear_solver.h"
46 #include "ceres/small_blas.h"
47 #include "glog/logging.h"
48 
49 namespace ceres {
50 namespace internal {
51 
52 // Given generalized bi-partite matrix A = [E F], with the same block
53 // structure as required by the Schur complement based solver, found
54 // in explicit_schur_complement_solver.h, provide access to the
55 // matrices E and F and their outer products E'E and F'F with
56 // themselves.
57 //
58 // Lack of BlockStructure object will result in a crash and if the
59 // block structure of the matrix does not satisfy the requirements of
60 // the Schur complement solver it will result in unpredictable and
61 // wrong output.
62 class PartitionedMatrixViewBase {
63  public:
~PartitionedMatrixViewBase()64   virtual ~PartitionedMatrixViewBase() {}
65 
66   // y += E'x
67   virtual void LeftMultiplyE(const double* x, double* y) const = 0;
68 
69   // y += F'x
70   virtual void LeftMultiplyF(const double* x, double* y) const = 0;
71 
72   // y += Ex
73   virtual void RightMultiplyE(const double* x, double* y) const = 0;
74 
75   // y += Fx
76   virtual void RightMultiplyF(const double* x, double* y) const = 0;
77 
78   // Create and return the block diagonal of the matrix E'E.
79   virtual BlockSparseMatrix* CreateBlockDiagonalEtE() const = 0;
80 
81   // Create and return the block diagonal of the matrix F'F. Caller
82   // owns the result.
83   virtual BlockSparseMatrix* CreateBlockDiagonalFtF() const = 0;
84 
85   // Compute the block diagonal of the matrix E'E and store it in
86   // block_diagonal. The matrix block_diagonal is expected to have a
87   // BlockStructure (preferably created using
88   // CreateBlockDiagonalMatrixEtE) which is has the same structure as
89   // the block diagonal of E'E.
90   virtual void UpdateBlockDiagonalEtE(
91       BlockSparseMatrix* block_diagonal) const = 0;
92 
93   // Compute the block diagonal of the matrix F'F and store it in
94   // block_diagonal. The matrix block_diagonal is expected to have a
95   // BlockStructure (preferably created using
96   // CreateBlockDiagonalMatrixFtF) which is has the same structure as
97   // the block diagonal of F'F.
98   virtual void UpdateBlockDiagonalFtF(
99       BlockSparseMatrix* block_diagonal) const = 0;
100 
101   virtual int num_col_blocks_e() const = 0;
102   virtual int num_col_blocks_f() const = 0;
103   virtual int num_cols_e()       const = 0;
104   virtual int num_cols_f()       const = 0;
105   virtual int num_rows()         const = 0;
106   virtual int num_cols()         const = 0;
107 
108   static PartitionedMatrixViewBase* Create(const LinearSolver::Options& options,
109                                            const BlockSparseMatrix& matrix);
110 };
111 
112 template <int kRowBlockSize = Eigen::Dynamic,
113           int kEBlockSize = Eigen::Dynamic,
114           int kFBlockSize = Eigen::Dynamic >
115 class PartitionedMatrixView : public PartitionedMatrixViewBase {
116  public:
117   // matrix = [E F], where the matrix E contains the first
118   // num_col_blocks_a column blocks.
119   PartitionedMatrixView(const BlockSparseMatrix& matrix, int num_col_blocks_e);
120 
121   virtual ~PartitionedMatrixView();
122   virtual void LeftMultiplyE(const double* x, double* y) const;
123   virtual void LeftMultiplyF(const double* x, double* y) const;
124   virtual void RightMultiplyE(const double* x, double* y) const;
125   virtual void RightMultiplyF(const double* x, double* y) const;
126   virtual BlockSparseMatrix* CreateBlockDiagonalEtE() const;
127   virtual BlockSparseMatrix* CreateBlockDiagonalFtF() const;
128   virtual void UpdateBlockDiagonalEtE(BlockSparseMatrix* block_diagonal) const;
129   virtual void UpdateBlockDiagonalFtF(BlockSparseMatrix* block_diagonal) const;
num_col_blocks_e()130   virtual int num_col_blocks_e() const { return num_col_blocks_e_;  }
num_col_blocks_f()131   virtual int num_col_blocks_f() const { return num_col_blocks_f_;  }
num_cols_e()132   virtual int num_cols_e()       const { return num_cols_e_;        }
num_cols_f()133   virtual int num_cols_f()       const { return num_cols_f_;        }
num_rows()134   virtual int num_rows()         const { return matrix_.num_rows(); }
num_cols()135   virtual int num_cols()         const { return matrix_.num_cols(); }
136 
137  private:
138   BlockSparseMatrix* CreateBlockDiagonalMatrixLayout(int start_col_block,
139                                                      int end_col_block) const;
140 
141   const BlockSparseMatrix& matrix_;
142   int num_row_blocks_e_;
143   int num_col_blocks_e_;
144   int num_col_blocks_f_;
145   int num_cols_e_;
146   int num_cols_f_;
147 };
148 
149 }  // namespace internal
150 }  // namespace ceres
151 
152 #endif  // CERES_INTERNAL_PARTITIONED_MATRIX_VIEW_H_
153