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_TRIPLET_SPARSE_MATRIX_H_ 32 #define CERES_INTERNAL_TRIPLET_SPARSE_MATRIX_H_ 33 34 #include <memory> 35 #include <vector> 36 #include "ceres/sparse_matrix.h" 37 #include "ceres/internal/eigen.h" 38 #include "ceres/types.h" 39 40 namespace ceres { 41 namespace internal { 42 43 // An implementation of the SparseMatrix interface to store and 44 // manipulate sparse matrices in triplet (i,j,s) form. This object is 45 // inspired by the design of the cholmod_triplet struct used in the 46 // SuiteSparse package and is memory layout compatible with it. 47 class TripletSparseMatrix : public SparseMatrix { 48 public: 49 TripletSparseMatrix(); 50 TripletSparseMatrix(int num_rows, int num_cols, int max_num_nonzeros); 51 TripletSparseMatrix(int num_rows, 52 int num_cols, 53 const std::vector<int>& rows, 54 const std::vector<int>& cols, 55 const std::vector<double>& values); 56 57 explicit TripletSparseMatrix(const TripletSparseMatrix& orig); 58 59 TripletSparseMatrix& operator=(const TripletSparseMatrix& rhs); 60 61 virtual ~TripletSparseMatrix(); 62 63 // Implementation of the SparseMatrix interface. 64 void SetZero() final; 65 void RightMultiply(const double* x, double* y) const final; 66 void LeftMultiply(const double* x, double* y) const final; 67 void SquaredColumnNorm(double* x) const final; 68 void ScaleColumns(const double* scale) final; 69 void ToDenseMatrix(Matrix* dense_matrix) const final; 70 void ToTextFile(FILE* file) const final; num_rows()71 int num_rows() const final { return num_rows_; } num_cols()72 int num_cols() const final { return num_cols_; } num_nonzeros()73 int num_nonzeros() const final { return num_nonzeros_; } values()74 const double* values() const final { return values_.get(); } mutable_values()75 double* mutable_values() final { return values_.get(); } 76 void set_num_nonzeros(int num_nonzeros); 77 78 // Increase max_num_nonzeros and correspondingly increase the size 79 // of rows_, cols_ and values_. If new_max_num_nonzeros is smaller 80 // than max_num_nonzeros_, then num_non_zeros should be less than or 81 // equal to new_max_num_nonzeros, otherwise data loss is possible 82 // and the method crashes. 83 void Reserve(int new_max_num_nonzeros); 84 85 // Append the matrix B at the bottom of this matrix. B should have 86 // the same number of columns as num_cols_. 87 void AppendRows(const TripletSparseMatrix& B); 88 89 // Append the matrix B at the right of this matrix. B should have 90 // the same number of rows as num_rows_; 91 void AppendCols(const TripletSparseMatrix& B); 92 93 // Resize the matrix. Entries which fall outside the new matrix 94 // bounds are dropped and the num_non_zeros changed accordingly. 95 void Resize(int new_num_rows, int new_num_cols); 96 max_num_nonzeros()97 int max_num_nonzeros() const { return max_num_nonzeros_; } rows()98 const int* rows() const { return rows_.get(); } cols()99 const int* cols() const { return cols_.get(); } mutable_rows()100 int* mutable_rows() { return rows_.get(); } mutable_cols()101 int* mutable_cols() { return cols_.get(); } 102 103 // Returns true if the entries of the matrix obey the row, column, 104 // and column size bounds and false otherwise. 105 bool AllTripletsWithinBounds() const; 106 IsValid()107 bool IsValid() const { return AllTripletsWithinBounds(); } 108 109 // Build a sparse diagonal matrix of size num_rows x num_rows from 110 // the array values. Entries of the values array are copied into the 111 // sparse matrix. 112 static TripletSparseMatrix* CreateSparseDiagonalMatrix(const double* values, 113 int num_rows); 114 115 // Options struct to control the generation of random 116 // TripletSparseMatrix objects. 117 struct RandomMatrixOptions { 118 int num_rows; 119 int num_cols; 120 // 0 < density <= 1 is the probability of an entry being 121 // structurally non-zero. A given random matrix will not have 122 // precisely this density. 123 double density; 124 }; 125 126 // Create a random CompressedRowSparseMatrix whose entries are 127 // normally distributed and whose structure is determined by 128 // RandomMatrixOptions. 129 // 130 // Caller owns the result. 131 static TripletSparseMatrix* CreateRandomMatrix( 132 const TripletSparseMatrix::RandomMatrixOptions& options); 133 134 private: 135 void AllocateMemory(); 136 void CopyData(const TripletSparseMatrix& orig); 137 138 int num_rows_; 139 int num_cols_; 140 int max_num_nonzeros_; 141 int num_nonzeros_; 142 143 // The data is stored as three arrays. For each i, values_[i] is 144 // stored at the location (rows_[i], cols_[i]). If the there are 145 // multiple entries with the same (rows_[i], cols_[i]), the values_ 146 // entries corresponding to them are summed up. 147 std::unique_ptr<int[]> rows_; 148 std::unique_ptr<int[]> cols_; 149 std::unique_ptr<double[]> values_; 150 }; 151 152 } // namespace internal 153 } // namespace ceres 154 155 #endif // CERES_INTERNAL_TRIPLET_SPARSE_MATRIX_H__ 156