1 // Ceres Solver - A fast non-linear least squares minimizer 2 // Copyright 2010, 2011, 2012 Google Inc. All rights reserved. 3 // http://code.google.com/p/ceres-solver/ 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 // Block structure objects are used to carry information about the 32 // dense block structure of sparse matrices. The BlockSparseMatrix 33 // object uses the BlockStructure objects to keep track of the matrix 34 // structure and operate upon it. This allows us to use more cache 35 // friendly block oriented linear algebra operations on the matrix 36 // instead of accessing it one scalar entry at a time. 37 38 #ifndef CERES_INTERNAL_BLOCK_STRUCTURE_H_ 39 #define CERES_INTERNAL_BLOCK_STRUCTURE_H_ 40 41 #include <vector> 42 #include "ceres/internal/port.h" 43 #include "ceres/types.h" 44 45 namespace ceres { 46 namespace internal { 47 48 class BlockStructureProto; 49 50 typedef int16 BlockSize; 51 52 struct Block { BlockBlock53 Block() : size(-1), position(-1) {} BlockBlock54 Block(int size_, int position_) : size(size_), position(position_) {} 55 56 BlockSize size; 57 int position; // Position along the row/column. 58 }; 59 60 struct Cell { CellCell61 Cell() : block_id(-1), position(-1) {} CellCell62 Cell(int block_id_, int position_) 63 : block_id(block_id_), position(position_) {} 64 65 // Column or row block id as the case maybe. 66 int block_id; 67 // Where in the values array of the jacobian is this cell located. 68 int position; 69 }; 70 71 // Order cell by their block_id; 72 bool CellLessThan(const Cell& lhs, const Cell& rhs); 73 74 struct CompressedList { 75 Block block; 76 vector<Cell> cells; 77 }; 78 79 typedef CompressedList CompressedRow; 80 typedef CompressedList CompressedColumn; 81 82 struct CompressedRowBlockStructure { 83 vector<Block> cols; 84 vector<CompressedRow> rows; 85 }; 86 87 struct CompressedColumnBlockStructure { 88 vector<Block> rows; 89 vector<CompressedColumn> cols; 90 }; 91 92 // Deserialize the given block structure proto to the given block structure. 93 // Destroys previous contents of block_structure. 94 void ProtoToBlockStructure(const BlockStructureProto &proto, 95 CompressedRowBlockStructure *block_structure); 96 97 // Serialize the given block structure to the given proto. Destroys previous 98 // contents of proto. 99 void BlockStructureToProto(const CompressedRowBlockStructure &block_structure, 100 BlockStructureProto *proto); 101 102 } // namespace internal 103 } // namespace ceres 104 105 #endif // CERES_INTERNAL_BLOCK_STRUCTURE_H_ 106