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      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: keir (at) google.com (Keir Mierle)
     30 
     31 #ifndef CERES_INTERNAL_PROGRAM_H_
     32 #define CERES_INTERNAL_PROGRAM_H_
     33 
     34 #include <string>
     35 #include <vector>
     36 #include "ceres/internal/port.h"
     37 
     38 namespace ceres {
     39 namespace internal {
     40 
     41 class ParameterBlock;
     42 class ProblemImpl;
     43 class ResidualBlock;
     44 
     45 // A nonlinear least squares optimization problem. This is different from the
     46 // similarly-named "Problem" object, which offers a mutation interface for
     47 // adding and modifying parameters and residuals. The Program contains the core
     48 // part of the Problem, which is the parameters and the residuals, stored in a
     49 // particular ordering. The ordering is critical, since it defines the mapping
     50 // between (residual, parameter) pairs and a position in the jacobian of the
     51 // objective function. Various parts of Ceres transform one Program into
     52 // another; for example, the first stage of solving involves stripping all
     53 // constant parameters and residuals. This is in contrast with Problem, which is
     54 // not built for transformation.
     55 class Program {
     56  public:
     57   Program();
     58   explicit Program(const Program& program);
     59 
     60   // The ordered parameter and residual blocks for the program.
     61   const vector<ParameterBlock*>& parameter_blocks() const;
     62   const vector<ResidualBlock*>& residual_blocks() const;
     63   vector<ParameterBlock*>* mutable_parameter_blocks();
     64   vector<ResidualBlock*>* mutable_residual_blocks();
     65 
     66   // Serialize to/from the program and update states.
     67   //
     68   // NOTE: Setting the state of a parameter block can trigger the
     69   // computation of the Jacobian of its local parameterization. If
     70   // this computation fails for some reason, then this method returns
     71   // false and the state of the parameter blocks cannot be trusted.
     72   bool StateVectorToParameterBlocks(const double *state);
     73   void ParameterBlocksToStateVector(double *state) const;
     74 
     75   // Copy internal state to the user's parameters.
     76   void CopyParameterBlockStateToUserState();
     77 
     78   // Set the parameter block pointers to the user pointers. Since this
     79   // runs parameter block set state internally, which may call local
     80   // parameterizations, this can fail. False is returned on failure.
     81   bool SetParameterBlockStatePtrsToUserStatePtrs();
     82 
     83   // Update a state vector for the program given a delta.
     84   bool Plus(const double* state,
     85             const double* delta,
     86             double* state_plus_delta) const;
     87 
     88   // Set the parameter indices and offsets. This permits mapping backward
     89   // from a ParameterBlock* to an index in the parameter_blocks() vector. For
     90   // any parameter block p, after calling SetParameterOffsetsAndIndex(), it
     91   // is true that
     92   //
     93   //   parameter_blocks()[p->index()] == p
     94   //
     95   // If a parameter appears in a residual but not in the parameter block, then
     96   // it will have an index of -1.
     97   //
     98   // This also updates p->state_offset() and p->delta_offset(), which are the
     99   // position of the parameter in the state and delta vector respectively.
    100   void SetParameterOffsetsAndIndex();
    101 
    102   // See problem.h for what these do.
    103   int NumParameterBlocks() const;
    104   int NumParameters() const;
    105   int NumEffectiveParameters() const;
    106   int NumResidualBlocks() const;
    107   int NumResiduals() const;
    108 
    109   int MaxScratchDoublesNeededForEvaluate() const;
    110   int MaxDerivativesPerResidualBlock() const;
    111   int MaxParametersPerResidualBlock() const;
    112   int MaxResidualsPerResidualBlock() const;
    113 
    114   // A human-readable dump of the parameter blocks for debugging.
    115   // TODO(keir): If necessary, also dump the residual blocks.
    116   string ToString() const;
    117 
    118  private:
    119   // The Program does not own the ParameterBlock or ResidualBlock objects.
    120   vector<ParameterBlock*> parameter_blocks_;
    121   vector<ResidualBlock*> residual_blocks_;
    122 
    123   friend class ProblemImpl;
    124 };
    125 
    126 }  // namespace internal
    127 }  // namespace ceres
    128 
    129 #endif  // CERES_INTERNAL_PROGRAM_H_
    130