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Diffstat (limited to 'internal/ceres/residual_block.h')
-rw-r--r-- | internal/ceres/residual_block.h | 124 |
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diff --git a/internal/ceres/residual_block.h b/internal/ceres/residual_block.h new file mode 100644 index 0000000..e0a06e7 --- /dev/null +++ b/internal/ceres/residual_block.h @@ -0,0 +1,124 @@ +// Ceres Solver - A fast non-linear least squares minimizer +// Copyright 2010, 2011, 2012 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 +// specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +// POSSIBILITY OF SUCH DAMAGE. +// +// Author: sameeragarwal@google.com (Sameer Agarwal) +// keir@google.com (Keir Mierle) +// +// Purpose : Class and struct definitions for parameter and residual blocks. + +#ifndef CERES_INTERNAL_RESIDUAL_BLOCK_H_ +#define CERES_INTERNAL_RESIDUAL_BLOCK_H_ + +#include <vector> + +#include "ceres/cost_function.h" +#include "ceres/internal/port.h" +#include "ceres/internal/scoped_ptr.h" +#include "ceres/types.h" + +namespace ceres { + +class LossFunction; + +namespace internal { + +class ParameterBlock; + +// A term in the least squares problem. The mathematical form of each term in +// the overall least-squares cost function is: +// +// 1 +// --- loss_function( || cost_function(block1, block2, ...) ||^2 ), +// 2 +// +// Storing the cost function and the loss function separately permits optimizing +// the problem with standard non-linear least techniques, without requiring a +// more general non-linear solver. +// +// The residual block stores pointers to but does not own the cost functions, +// loss functions, and parameter blocks. +class ResidualBlock { + public: + ResidualBlock(const CostFunction* cost_function, + const LossFunction* loss_function, + const vector<ParameterBlock*>& parameter_blocks); + + // Evaluates the residual term, storing the scalar cost in *cost, the residual + // components in *residuals, and the jacobians between the parameters and + // residuals in jacobians[i], in row-major order. If residuals is NULL, the + // residuals are not computed. If jacobians is NULL, no jacobians are + // computed. If jacobians[i] is NULL, then the jacobian for that parameter is + // not computed. + // + // Evaluate needs scratch space which must be supplied by the caller via + // scratch. The array should have at least NumScratchDoublesForEvaluate() + // space available. + // + // The return value indicates the success or failure. If the function returns + // false, the caller should expect the the output memory locations to have + // been modified. + // + // The returned cost and jacobians have had robustification and local + // parameterizations applied already; for example, the jacobian for a + // 4-dimensional quaternion parameter using the "QuaternionParameterization" + // is num_residuals by 3 instead of num_residuals by 4. + bool Evaluate(double* cost, + double* residuals, + double** jacobians, + double* scratch) const; + + const CostFunction* cost_function() const { return cost_function_; } + const LossFunction* loss_function() const { return loss_function_; } + + // Access the parameter blocks for this residual. The array has size + // NumParameterBlocks(). + ParameterBlock* const* parameter_blocks() const { + return parameter_blocks_.get(); + } + + // Number of variable blocks that this residual term depends on. + int NumParameterBlocks() const { + return cost_function_->parameter_block_sizes().size(); + } + + // The size of the residual vector returned by this residual function. + int NumResiduals() const { return cost_function_->num_residuals(); } + + // The minimum amount of scratch space needed to pass to Evaluate(). + int NumScratchDoublesForEvaluate() const; + + private: + const CostFunction* cost_function_; + const LossFunction* loss_function_; + scoped_array<ParameterBlock*> parameter_blocks_; +}; + +} // namespace internal +} // namespace ceres + +#endif // CERES_INTERNAL_RESIDUAL_BLOCK_H_ |