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@google.com (Sameer Agarwal) 30 // 31 // Compute a parameter block ordering for use with the Schur 32 // complement based algorithms. 33 34 #ifndef CERES_INTERNAL_SCHUR_ORDERING_H_ 35 #define CERES_INTERNAL_SCHUR_ORDERING_H_ 36 37 #include <vector> 38 #include "ceres/graph.h" 39 #include "ceres/types.h" 40 41 namespace ceres { 42 namespace internal { 43 44 class Program; 45 class ParameterBlock; 46 47 // Uses an approximate independent set ordering to order the parameter 48 // blocks of a problem so that it is suitable for use with Schur 49 // complement based solvers. The output variable ordering contains an 50 // ordering of the parameter blocks and the return value is size of 51 // the independent set or the number of e_blocks (see 52 // schur_complement_solver.h for an explanation). Constant parameters 53 // are added to the end. 54 // 55 // The ordering vector has the structure 56 // 57 // ordering = [independent set, 58 // complement of the independent set, 59 // fixed blocks] 60 int ComputeSchurOrdering(const Program& program, 61 vector<ParameterBlock* >* ordering); 62 63 64 // Builds a graph on the parameter blocks of a Problem, whose 65 // structure reflects the sparsity structure of the Hessian. Each 66 // vertex corresponds to a parameter block in the Problem except for 67 // parameter blocks that are marked constant. An edge connects two 68 // parameter blocks, if they co-occur in a residual block. 69 Graph<ParameterBlock*>* CreateHessianGraph(const Program& program); 70 71 } // namespace internal 72 } // namespace ceres 73 74 #endif // CERES_INTERNAL_SCHUR_ORDERING_H_ 75