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: keir@google.com (Keir Mierle)
31 #include "ceres/block_jacobi_preconditioner.h"
33 #include "ceres/block_sparse_matrix.h"
34 #include "ceres/block_structure.h"
35 #include "ceres/block_random_access_diagonal_matrix.h"
36 #include "ceres/casts.h"
37 #include "ceres/integral_types.h"
38 #include "ceres/internal/eigen.h"
43 BlockJacobiPreconditioner::BlockJacobiPreconditioner(
44 const BlockSparseMatrix& A) {
45 const CompressedRowBlockStructure* bs = A.block_structure();
46 std::vector<int> blocks(bs->cols.size());
47 for (int i = 0; i < blocks.size(); ++i) {
48 blocks[i] = bs->cols[i].size;
51 m_.reset(new BlockRandomAccessDiagonalMatrix(blocks));
54 BlockJacobiPreconditioner::~BlockJacobiPreconditioner() {}
56 bool BlockJacobiPreconditioner::UpdateImpl(const BlockSparseMatrix& A,
58 const CompressedRowBlockStructure* bs = A.block_structure();
59 const double* values = A.values();
61 for (int i = 0; i < bs->rows.size(); ++i) {
62 const int row_block_size = bs->rows[i].block.size;
63 const std::vector<Cell>& cells = bs->rows[i].cells;
64 for (int j = 0; j < cells.size(); ++j) {
65 const int block_id = cells[j].block_id;
66 const int col_block_size = bs->cols[block_id].size;
68 int r, c, row_stride, col_stride;
69 CellInfo* cell_info = m_->GetCell(block_id, block_id,
71 &row_stride, &col_stride);
72 MatrixRef m(cell_info->values, row_stride, col_stride);
73 ConstMatrixRef b(values + cells[j].position,
76 m.block(r, c, col_block_size, col_block_size) += b.transpose() * b;
83 for (int i = 0; i < bs->cols.size(); ++i) {
84 const int block_size = bs->cols[i].size;
85 int r, c, row_stride, col_stride;
86 CellInfo* cell_info = m_->GetCell(i, i,
88 &row_stride, &col_stride);
89 MatrixRef m(cell_info->values, row_stride, col_stride);
90 m.block(r, c, block_size, block_size).diagonal() +=
91 ConstVectorRef(D + position, block_size).array().square().matrix();
92 position += block_size;
100 void BlockJacobiPreconditioner::RightMultiply(const double* x,
102 m_->RightMultiply(x, y);
105 } // namespace internal