1 // Ceres Solver - A fast non-linear least squares minimizer
2 // Copyright 2015 Google Inc. All rights reserved.
3 // http://ceres-solver.org/
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29 // Author: sameeragarwal@google.com (Sameer Agarwal)
31 // Detailed descriptions of these preconditions beyond what is
32 // documented here can be found in
34 // Bundle Adjustment in the Large
35 // S. Agarwal, N. Snavely, S. Seitz & R. Szeliski, ECCV 2010
36 // http://www.cs.washington.edu/homes/sagarwal/bal.pdf
38 #ifndef CERES_INTERNAL_SCHUR_JACOBI_PRECONDITIONER_H_
39 #define CERES_INTERNAL_SCHUR_JACOBI_PRECONDITIONER_H_
44 #include "ceres/collections_port.h"
45 #include "ceres/internal/macros.h"
46 #include "ceres/internal/scoped_ptr.h"
47 #include "ceres/preconditioner.h"
52 class BlockRandomAccessDiagonalMatrix;
53 class BlockSparseMatrix;
54 struct CompressedRowBlockStructure;
55 class SchurEliminatorBase;
57 // This class implements the SCHUR_JACOBI preconditioner for Structure
58 // from Motion/Bundle Adjustment problems. Full mathematical details
61 // Bundle Adjustment in the Large
62 // S. Agarwal, N. Snavely, S. Seitz & R. Szeliski, ECCV 2010
63 // http://www.cs.washington.edu/homes/sagarwal/bal.pdf
67 // Preconditioner::Options options;
68 // options.preconditioner_type = SCHUR_JACOBI;
69 // options.elimination_groups.push_back(num_points);
70 // options.elimination_groups.push_back(num_cameras);
71 // SchurJacobiPreconditioner preconditioner(
72 // *A.block_structure(), options);
73 // preconditioner.Update(A, NULL);
74 // preconditioner.RightMultiply(x, y);
76 class SchurJacobiPreconditioner : public BlockSparseMatrixPreconditioner {
78 // Initialize the symbolic structure of the preconditioner. bs is
79 // the block structure of the linear system to be solved. It is used
80 // to determine the sparsity structure of the preconditioner matrix.
82 // It has the same structural requirement as other Schur complement
83 // based solvers. Please see schur_eliminator.h for more details.
84 SchurJacobiPreconditioner(const CompressedRowBlockStructure& bs,
85 const Preconditioner::Options& options);
86 virtual ~SchurJacobiPreconditioner();
88 // Preconditioner interface.
89 virtual void RightMultiply(const double* x, double* y) const;
90 virtual int num_rows() const;
93 void InitEliminator(const CompressedRowBlockStructure& bs);
94 virtual bool UpdateImpl(const BlockSparseMatrix& A, const double* D);
96 Preconditioner::Options options_;
97 scoped_ptr<SchurEliminatorBase> eliminator_;
98 // Preconditioner matrix.
99 scoped_ptr<BlockRandomAccessDiagonalMatrix> m_;
100 CERES_DISALLOW_COPY_AND_ASSIGN(SchurJacobiPreconditioner);
103 } // namespace internal
106 #endif // CERES_INTERNAL_SCHUR_JACOBI_PRECONDITIONER_H_