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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6 // modification, are permitted provided that the following conditions are met:
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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
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15 // specific prior written permission.
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29 // Author: sameeragarwal@google.com (Sameer Agarwal)
31 #ifndef CERES_INTERNAL_TRIPLET_SPARSE_MATRIX_H_
32 #define CERES_INTERNAL_TRIPLET_SPARSE_MATRIX_H_
35 #include "ceres/sparse_matrix.h"
36 #include "ceres/internal/eigen.h"
37 #include "ceres/internal/scoped_ptr.h"
38 #include "ceres/types.h"
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 {
49 TripletSparseMatrix();
50 TripletSparseMatrix(int num_rows, int num_cols, int max_num_nonzeros);
51 TripletSparseMatrix(int num_rows,
53 const std::vector<int>& rows,
54 const std::vector<int>& cols,
55 const std::vector<double>& values);
57 explicit TripletSparseMatrix(const TripletSparseMatrix& orig);
59 TripletSparseMatrix& operator=(const TripletSparseMatrix& rhs);
61 ~TripletSparseMatrix();
63 // Implementation of the SparseMatrix interface.
64 virtual void SetZero();
65 virtual void RightMultiply(const double* x, double* y) const;
66 virtual void LeftMultiply(const double* x, double* y) const;
67 virtual void SquaredColumnNorm(double* x) const;
68 virtual void ScaleColumns(const double* scale);
69 virtual void ToDenseMatrix(Matrix* dense_matrix) const;
70 virtual void ToTextFile(FILE* file) const;
71 virtual int num_rows() const { return num_rows_; }
72 virtual int num_cols() const { return num_cols_; }
73 virtual int num_nonzeros() const { return num_nonzeros_; }
74 virtual const double* values() const { return values_.get(); }
75 virtual double* mutable_values() { return values_.get(); }
76 virtual void set_num_nonzeros(int num_nonzeros);
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);
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);
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);
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);
97 int max_num_nonzeros() const { return max_num_nonzeros_; }
98 const int* rows() const { return rows_.get(); }
99 const int* cols() const { return cols_.get(); }
100 int* mutable_rows() { return rows_.get(); }
101 int* mutable_cols() { return cols_.get(); }
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;
107 bool IsValid() const { return AllTripletsWithinBounds(); }
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
112 static TripletSparseMatrix* CreateSparseDiagonalMatrix(const double* values,
115 // Options struct to control the generation of random
116 // TripletSparseMatrix objects.
117 struct RandomMatrixOptions {
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.
126 // Create a random CompressedRowSparseMatrix whose entries are
127 // normally distributed and whose structure is determined by
128 // RandomMatrixOptions.
130 // Caller owns the result.
131 static TripletSparseMatrix* CreateRandomMatrix(
132 const TripletSparseMatrix::RandomMatrixOptions& options);
135 void AllocateMemory();
136 void CopyData(const TripletSparseMatrix& orig);
140 int max_num_nonzeros_;
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 scoped_array<int> rows_;
148 scoped_array<int> cols_;
149 scoped_array<double> values_;
152 } // namespace internal
155 #endif // CERES_INTERNAL_TRIPLET_SPARSE_MATRIX_H__