// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2014 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
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//
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// Author: sameeragarwal@google.com (Sameer Agarwal)
#ifndef CERES_INTERNAL_REORDER_PROGRAM_H_
#define CERES_INTERNAL_REORDER_PROGRAM_H_
#include <string>
#include "ceres/internal/port.h"
#include "ceres/parameter_block_ordering.h"
#include "ceres/problem_impl.h"
#include "ceres/types.h"
namespace ceres {
namespace internal {
class Program;
// Reorder the parameter blocks in program using the ordering
bool ApplyOrdering(const ProblemImpl::ParameterMap& parameter_map,
const ParameterBlockOrdering& ordering,
Program* program,
string* error);
// Reorder the residuals for program, if necessary, so that the residuals
// involving each E block occur together. This is a necessary condition for the
// Schur eliminator, which works on these "row blocks" in the jacobian.
bool LexicographicallyOrderResidualBlocks(int num_eliminate_blocks,
Program* program,
string* error);
// Schur type solvers require that all parameter blocks eliminated
// by the Schur eliminator occur before others and the residuals be
// sorted in lexicographic order of their parameter blocks.
//
// If the parameter_block_ordering only contains one elimination
// group then a maximal independent set is computed and used as the
// first elimination group, otherwise the user's ordering is used.
//
// If the linear solver type is SPARSE_SCHUR and support for
// constrained fill-reducing ordering is available in the sparse
// linear algebra library (SuiteSparse version >= 4.2.0) then
// columns of the schur complement matrix are ordered to reduce the
// fill-in the Cholesky factorization.
//
// Upon return, ordering contains the parameter block ordering that
// was used to order the program.
bool ReorderProgramForSchurTypeLinearSolver(
LinearSolverType linear_solver_type,
SparseLinearAlgebraLibraryType sparse_linear_algebra_library_type,
const ProblemImpl::ParameterMap& parameter_map,
ParameterBlockOrdering* parameter_block_ordering,
Program* program,
string* error);
// Sparse cholesky factorization routines when doing the sparse
// cholesky factorization of the Jacobian matrix, reorders its
// columns to reduce the fill-in. Compute this permutation and
// re-order the parameter blocks.
//
// When using SuiteSparse, if the parameter_block_ordering contains
// more than one elimination group and support for constrained
// fill-reducing ordering is available in the sparse linear algebra
// library (SuiteSparse version >= 4.2.0) then the fill reducing
// ordering will take it into account, otherwise it will be ignored.
bool ReorderProgramForSparseNormalCholesky(
SparseLinearAlgebraLibraryType sparse_linear_algebra_library_type,
const ParameterBlockOrdering& parameter_block_ordering,
Program* program,
string* error);
} // namespace internal
} // namespace ceres
#endif // CERES_INTERNAL_REORDER_PROGRAM_