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//
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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,
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12//   and/or other materials provided with the distribution.
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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
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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 "ceres/sparse_matrix.h"
35#include "ceres/internal/eigen.h"
36#include "ceres/internal/scoped_ptr.h"
37#include "ceres/types.h"
38
39namespace ceres {
40namespace internal {
41
42class SparseMatrixProto;
43
44// An implementation of the SparseMatrix interface to store and
45// manipulate sparse matrices in triplet (i,j,s) form.  This object is
46// inspired by the design of the cholmod_triplet struct used in the
47// SuiteSparse package and is memory layout compatible with it.
48class TripletSparseMatrix : public SparseMatrix {
49 public:
50  TripletSparseMatrix();
51  TripletSparseMatrix(int num_rows, int num_cols, int max_num_nonzeros);
52  explicit TripletSparseMatrix(const TripletSparseMatrix& orig);
53#ifndef CERES_NO_PROTOCOL_BUFFERS
54  explicit TripletSparseMatrix(const SparseMatrixProto& proto);
55#endif
56
57  TripletSparseMatrix& operator=(const TripletSparseMatrix& rhs);
58
59  ~TripletSparseMatrix();
60
61  // Implementation of the SparseMatrix interface.
62  virtual void SetZero();
63  virtual void RightMultiply(const double* x, double* y) const;
64  virtual void LeftMultiply(const double* x, double* y) const;
65  virtual void SquaredColumnNorm(double* x) const;
66  virtual void ScaleColumns(const double* scale);
67  virtual void ToDenseMatrix(Matrix* dense_matrix) const;
68#ifndef CERES_NO_PROTOCOL_BUFFERS
69  virtual void ToProto(SparseMatrixProto *proto) const;
70#endif
71  virtual void ToTextFile(FILE* file) const;
72  virtual int num_rows()        const { return num_rows_;     }
73  virtual int num_cols()        const { return num_cols_;     }
74  virtual int num_nonzeros()    const { return num_nonzeros_; }
75  virtual const double* values()  const { return values_.get(); }
76  virtual double* mutable_values()      { return values_.get(); }
77  virtual void set_num_nonzeros(int num_nonzeros);
78
79  // Increase max_num_nonzeros and correspondingly increase the size
80  // of rows_, cols_ and values_. If new_max_num_nonzeros is smaller
81  // than max_num_nonzeros_, then num_non_zeros should be less than or
82  // equal to new_max_num_nonzeros, otherwise data loss is possible
83  // and the method crashes.
84  void Reserve(int new_max_num_nonzeros);
85
86  // Append the matrix B at the bottom of this matrix. B should have
87  // the same number of columns as num_cols_.
88  void AppendRows(const TripletSparseMatrix& B);
89
90  // Append the matrix B at the right of this matrix. B should have
91  // the same number of rows as num_rows_;
92  void AppendCols(const TripletSparseMatrix& B);
93
94  // Resize the matrix. Entries which fall outside the new matrix
95  // bounds are dropped and the num_non_zeros changed accordingly.
96  void Resize(int new_num_rows, int new_num_cols);
97
98  int max_num_nonzeros() const { return max_num_nonzeros_; }
99  const int* rows()      const { return rows_.get();       }
100  const int* cols()      const { return cols_.get();       }
101  int* mutable_rows()          { return rows_.get();       }
102  int* mutable_cols()          { return cols_.get();       }
103
104  // Returns true if the entries of the matrix obey the row, column,
105  // and column size bounds and false otherwise.
106  bool AllTripletsWithinBounds() const;
107
108  bool IsValid() const { return AllTripletsWithinBounds(); }
109
110  // Build a sparse diagonal matrix of size num_rows x num_rows from
111  // the array values. Entries of the values array are copied into the
112  // sparse matrix.
113  static TripletSparseMatrix* CreateSparseDiagonalMatrix(const double* values,
114                                                         int num_rows);
115
116 private:
117  void AllocateMemory();
118  void CopyData(const TripletSparseMatrix& orig);
119
120  int num_rows_;
121  int num_cols_;
122  int max_num_nonzeros_;
123  int num_nonzeros_;
124
125  // The data is stored as three arrays. For each i, values_[i] is
126  // stored at the location (rows_[i], cols_[i]). If the there are
127  // multiple entries with the same (rows_[i], cols_[i]), the values_
128  // entries corresponding to them are summed up.
129  scoped_array<int> rows_;
130  scoped_array<int> cols_;
131  scoped_array<double> values_;
132};
133
134}  // namespace internal
135}  // namespace ceres
136
137#endif  // CERES_INTERNAL_TRIPLET_SPARSE_MATRIX_H__
138