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 (at) google.com (Sameer Agarwal) 30 // 31 // Interface definition for sparse matrices. 32 33 #ifndef CERES_INTERNAL_SPARSE_MATRIX_H_ 34 #define CERES_INTERNAL_SPARSE_MATRIX_H_ 35 36 #include <cstdio> 37 #include "ceres/linear_operator.h" 38 #include "ceres/internal/eigen.h" 39 #include "ceres/types.h" 40 41 namespace ceres { 42 namespace internal { 43 44 // This class defines the interface for storing and manipulating 45 // sparse matrices. The key property that differentiates different 46 // sparse matrices is how they are organized in memory and how the 47 // information about the sparsity structure of the matrix is 48 // stored. This has significant implications for linear solvers 49 // operating on these matrices. 50 // 51 // To deal with the different kinds of layouts, we will assume that a 52 // sparse matrix will have a two part representation. A values array 53 // that will be used to store the entries of the sparse matrix and 54 // some sort of a layout object that tells the user the sparsity 55 // structure and layout of the values array. For example in case of 56 // the TripletSparseMatrix, this information is carried in the rows 57 // and cols arrays and for the BlockSparseMatrix, this information is 58 // carried in the CompressedRowBlockStructure object. 59 // 60 // This interface deliberately does not contain any information about 61 // the structure of the sparse matrix as that seems to be highly 62 // matrix type dependent and we are at this stage unable to come up 63 // with an efficient high level interface that spans multiple sparse 64 // matrix types. 65 class SparseMatrix : public LinearOperator { 66 public: 67 virtual ~SparseMatrix(); 68 69 // y += Ax; 70 virtual void RightMultiply(const double* x, double* y) const = 0; 71 // y += A'x; 72 virtual void LeftMultiply(const double* x, double* y) const = 0; 73 74 // In MATLAB notation sum(A.*A, 1) 75 virtual void SquaredColumnNorm(double* x) const = 0; 76 // A = A * diag(scale) 77 virtual void ScaleColumns(const double* scale) = 0; 78 79 // A = 0. A->num_nonzeros() == 0 is true after this call. The 80 // sparsity pattern is preserved. 81 virtual void SetZero() = 0; 82 83 // Resize and populate dense_matrix with a dense version of the 84 // sparse matrix. 85 virtual void ToDenseMatrix(Matrix* dense_matrix) const = 0; 86 87 // Write out the matrix as a sequence of (i,j,s) triplets. This 88 // format is useful for loading the matrix into MATLAB/octave as a 89 // sparse matrix. 90 virtual void ToTextFile(FILE* file) const = 0; 91 92 // Accessors for the values array that stores the entries of the 93 // sparse matrix. The exact interpreptation of the values of this 94 // array depends on the particular kind of SparseMatrix being 95 // accessed. 96 virtual double* mutable_values() = 0; 97 virtual const double* values() const = 0; 98 99 virtual int num_rows() const = 0; 100 virtual int num_cols() const = 0; 101 virtual int num_nonzeros() const = 0; 102 }; 103 104 } // namespace internal 105 } // namespace ceres 106 107 #endif // CERES_INTERNAL_SPARSE_MATRIX_H_ 108
