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 // 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 38 #include "ceres/internal/eigen.h" 39 #include "ceres/internal/port.h" 40 #include "ceres/linear_operator.h" 41 #include "ceres/types.h" 42 43 namespace ceres { 44 namespace internal { 45 46 // This class defines the interface for storing and manipulating 47 // sparse matrices. The key property that differentiates different 48 // sparse matrices is how they are organized in memory and how the 49 // information about the sparsity structure of the matrix is 50 // stored. This has significant implications for linear solvers 51 // operating on these matrices. 52 // 53 // To deal with the different kinds of layouts, we will assume that a 54 // sparse matrix will have a two part representation. A values array 55 // that will be used to store the entries of the sparse matrix and 56 // some sort of a layout object that tells the user the sparsity 57 // structure and layout of the values array. For example in case of 58 // the TripletSparseMatrix, this information is carried in the rows 59 // and cols arrays and for the BlockSparseMatrix, this information is 60 // carried in the CompressedRowBlockStructure object. 61 // 62 // This interface deliberately does not contain any information about 63 // the structure of the sparse matrix as that seems to be highly 64 // matrix type dependent and we are at this stage unable to come up 65 // with an efficient high level interface that spans multiple sparse 66 // matrix types. 67 class CERES_EXPORT_INTERNAL SparseMatrix : public LinearOperator { 68 public: 69 virtual ~SparseMatrix(); 70 71 // y += Ax; 72 virtual void RightMultiply(const double* x, double* y) const = 0; 73 // y += A'x; 74 virtual void LeftMultiply(const double* x, double* y) const = 0; 75 76 // In MATLAB notation sum(A.*A, 1) 77 virtual void SquaredColumnNorm(double* x) const = 0; 78 // A = A * diag(scale) 79 virtual void ScaleColumns(const double* scale) = 0; 80 81 // A = 0. A->num_nonzeros() == 0 is true after this call. The 82 // sparsity pattern is preserved. 83 virtual void SetZero() = 0; 84 85 // Resize and populate dense_matrix with a dense version of the 86 // sparse matrix. 87 virtual void ToDenseMatrix(Matrix* dense_matrix) const = 0; 88 89 // Write out the matrix as a sequence of (i,j,s) triplets. This 90 // format is useful for loading the matrix into MATLAB/octave as a 91 // sparse matrix. 92 virtual void ToTextFile(FILE* file) const = 0; 93 94 // Accessors for the values array that stores the entries of the 95 // sparse matrix. The exact interpretation of the values of this 96 // array depends on the particular kind of SparseMatrix being 97 // accessed. 98 virtual double* mutable_values() = 0; 99 virtual const double* values() const = 0; 100 101 virtual int num_rows() const = 0; 102 virtual int num_cols() const = 0; 103 virtual int num_nonzeros() const = 0; 104 }; 105 106 } // namespace internal 107 } // namespace ceres 108 109 #endif // CERES_INTERNAL_SPARSE_MATRIX_H_ 110