1 // Ceres Solver - A fast non-linear least squares minimizer 2 // Copyright 2015 Google Inc. All rights reserved. 3 // http://ceres-solver.org/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are met: 7 // 8 // * Redistributions of source code must retain the above copyright notice, 9 // this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above copyright notice, 11 // this list of conditions and the following disclaimer in the documentation 12 // and/or other materials provided with the distribution. 13 // * Neither the name of Google Inc. nor the names of its contributors may be 14 // used to endorse or promote products derived from this software without 15 // specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 18 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 21 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 // POSSIBILITY OF SUCH DAMAGE. 28 // 29 // Author: sameeragarwal@google.com (Sameer Agarwal) 30 31 #ifndef CERES_INTERNAL_BLOCK_RANDOM_ACCESS_SPARSE_MATRIX_H_ 32 #define CERES_INTERNAL_BLOCK_RANDOM_ACCESS_SPARSE_MATRIX_H_ 33 34 #include <cstdint> 35 #include <memory> 36 #include <set> 37 #include <unordered_map> 38 #include <utility> 39 #include <vector> 40 41 #include "ceres/block_random_access_matrix.h" 42 #include "ceres/internal/port.h" 43 #include "ceres/small_blas.h" 44 #include "ceres/triplet_sparse_matrix.h" 45 #include "ceres/types.h" 46 47 namespace ceres { 48 namespace internal { 49 50 // A thread safe square block sparse implementation of 51 // BlockRandomAccessMatrix. Internally a TripletSparseMatrix is used 52 // for doing the actual storage. This class augments this matrix with 53 // an unordered_map that allows random read/write access. 54 class CERES_EXPORT_INTERNAL BlockRandomAccessSparseMatrix 55 : public BlockRandomAccessMatrix { 56 public: 57 // blocks is an array of block sizes. block_pairs is a set of 58 // <row_block_id, col_block_id> pairs to identify the non-zero cells 59 // of this matrix. 60 BlockRandomAccessSparseMatrix( 61 const std::vector<int>& blocks, 62 const std::set<std::pair<int, int>>& block_pairs); 63 BlockRandomAccessSparseMatrix(const BlockRandomAccessSparseMatrix&) = delete; 64 void operator=(const BlockRandomAccessSparseMatrix&) = delete; 65 66 // The destructor is not thread safe. It assumes that no one is 67 // modifying any cells when the matrix is being destroyed. 68 virtual ~BlockRandomAccessSparseMatrix(); 69 70 // BlockRandomAccessMatrix Interface. 71 CellInfo* GetCell(int row_block_id, 72 int col_block_id, 73 int* row, 74 int* col, 75 int* row_stride, 76 int* col_stride) final; 77 78 // This is not a thread safe method, it assumes that no cell is 79 // locked. 80 void SetZero() final; 81 82 // Assume that the matrix is symmetric and only one half of the 83 // matrix is stored. 84 // 85 // y += S * x 86 void SymmetricRightMultiply(const double* x, double* y) const; 87 88 // Since the matrix is square, num_rows() == num_cols(). num_rows()89 int num_rows() const final { return tsm_->num_rows(); } num_cols()90 int num_cols() const final { return tsm_->num_cols(); } 91 92 // Access to the underlying matrix object. matrix()93 const TripletSparseMatrix* matrix() const { return tsm_.get(); } mutable_matrix()94 TripletSparseMatrix* mutable_matrix() { return tsm_.get(); } 95 96 private: IntPairToLong(int row,int col)97 int64_t IntPairToLong(int row, int col) const { 98 return row * kMaxRowBlocks + col; 99 } 100 LongToIntPair(int64_t index,int * row,int * col)101 void LongToIntPair(int64_t index, int* row, int* col) const { 102 *row = index / kMaxRowBlocks; 103 *col = index % kMaxRowBlocks; 104 } 105 106 const int64_t kMaxRowBlocks; 107 108 // row/column block sizes. 109 const std::vector<int> blocks_; 110 std::vector<int> block_positions_; 111 112 // A mapping from <row_block_id, col_block_id> to the position in 113 // the values array of tsm_ where the block is stored. 114 typedef std::unordered_map<long int, CellInfo*> LayoutType; 115 LayoutType layout_; 116 117 // In order traversal of contents of the matrix. This allows us to 118 // implement a matrix-vector which is 20% faster than using the 119 // iterator in the Layout object instead. 120 std::vector<std::pair<std::pair<int, int>, double*>> cell_values_; 121 // The underlying matrix object which actually stores the cells. 122 std::unique_ptr<TripletSparseMatrix> tsm_; 123 124 friend class BlockRandomAccessSparseMatrixTest; 125 }; 126 127 } // namespace internal 128 } // namespace ceres 129 130 #endif // CERES_INTERNAL_BLOCK_RANDOM_ACCESS_SPARSE_MATRIX_H_ 131