// 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: keir@google.com (Keir Mierle)
// sameeragarwal@google.com (Sameer Agarwal)
#include "ceres/residual_block.h"
#include <algorithm>
#include <cstddef>
#include <vector>
#include "ceres/corrector.h"
#include "ceres/parameter_block.h"
#include "ceres/residual_block_utils.h"
#include "ceres/cost_function.h"
#include "ceres/internal/eigen.h"
#include "ceres/internal/fixed_array.h"
#include "ceres/local_parameterization.h"
#include "ceres/loss_function.h"
namespace ceres {
namespace internal {
ResidualBlock::ResidualBlock(const CostFunction* cost_function,
const LossFunction* loss_function,
const vector<ParameterBlock*>& parameter_blocks)
: cost_function_(cost_function),
loss_function_(loss_function),
parameter_blocks_(
new ParameterBlock* [
cost_function->parameter_block_sizes().size()]) {
std::copy(parameter_blocks.begin(),
parameter_blocks.end(),
parameter_blocks_.get());
}
bool ResidualBlock::Evaluate(double* cost,
double* residuals,
double** jacobians,
double* scratch) const {
const int num_parameter_blocks = NumParameterBlocks();
const int num_residuals = cost_function_->num_residuals();
// Collect the parameters from their blocks. This will rarely allocate, since
// residuals taking more than 8 parameter block arguments are rare.
FixedArray<const double*, 8> parameters(num_parameter_blocks);
for (int i = 0; i < num_parameter_blocks; ++i) {
parameters[i] = parameter_blocks_[i]->state();
}
// Put pointers into the scratch space into global_jacobians as appropriate.
FixedArray<double*, 8> global_jacobians(num_parameter_blocks);
if (jacobians != NULL) {
for (int i = 0; i < num_parameter_blocks; ++i) {
const ParameterBlock* parameter_block = parameter_blocks_[i];
if (jacobians[i] != NULL &&
parameter_block->LocalParameterizationJacobian() != NULL) {
global_jacobians[i] = scratch;
scratch += num_residuals * parameter_block->Size();
} else {
global_jacobians[i] = jacobians[i];
}
}
}
// If the caller didn't request residuals, use the scratch space for them.
bool outputting_residuals = (residuals != NULL);
if (!outputting_residuals) {
residuals = scratch;
}
// Invalidate the evaluation buffers so that we can check them after
// the CostFunction::Evaluate call, to see if all the return values
// that were required were written to and that they are finite.
double** eval_jacobians = (jacobians != NULL) ? global_jacobians.get() : NULL;
InvalidateEvaluation(*this, cost, residuals, eval_jacobians);
if (!cost_function_->Evaluate(parameters.get(), residuals, eval_jacobians)) {
return false;
}
if (!IsEvaluationValid(*this,
parameters.get(),
cost,
residuals,
eval_jacobians)) {
string message =
"\n\n"
"Error in evaluating the ResidualBlock.\n\n"
"There are two possible reasons. Either the CostFunction did not evaluate and fill all \n" // NOLINT
"residual and jacobians that were requested or there was a non-finite value (nan/infinite)\n" // NOLINT
"generated during the or jacobian computation. \n\n" +
EvaluationToString(*this,
parameters.get(),
cost,
residuals,
eval_jacobians);
LOG(WARNING) << message;
return false;
}
double squared_norm = VectorRef(residuals, num_residuals).squaredNorm();
// Update the jacobians with the local parameterizations.
if (jacobians != NULL) {
for (int i = 0; i < num_parameter_blocks; ++i) {
if (jacobians[i] != NULL) {
const ParameterBlock* parameter_block = parameter_blocks_[i];
// Apply local reparameterization to the jacobians.
if (parameter_block->LocalParameterizationJacobian() != NULL) {
ConstMatrixRef local_to_global(
parameter_block->LocalParameterizationJacobian(),
parameter_block->Size(),
parameter_block->LocalSize());
MatrixRef global_jacobian(global_jacobians[i],
num_residuals,
parameter_block->Size());
MatrixRef local_jacobian(jacobians[i],
num_residuals,
parameter_block->LocalSize());
local_jacobian.noalias() = global_jacobian * local_to_global;
}
}
}
}
if (loss_function_ == NULL) {
*cost = 0.5 * squared_norm;
return true;
}
double rho[3];
loss_function_->Evaluate(squared_norm, rho);
*cost = 0.5 * rho[0];
// No jacobians and not outputting residuals? All done. Doing an early exit
// here avoids constructing the "Corrector" object below in a common case.
if (jacobians == NULL && !outputting_residuals) {
return true;
}
// Correct for the effects of the loss function. The jacobians need to be
// corrected before the residuals, since they use the uncorrected residuals.
Corrector correct(squared_norm, rho);
if (jacobians != NULL) {
for (int i = 0; i < num_parameter_blocks; ++i) {
if (jacobians[i] != NULL) {
const ParameterBlock* parameter_block = parameter_blocks_[i];
// Correct the jacobians for the loss function.
correct.CorrectJacobian(num_residuals,
parameter_block->LocalSize(),
residuals,
jacobians[i]);
}
}
}
// Correct the residuals with the loss function.
if (outputting_residuals) {
correct.CorrectResiduals(num_residuals, residuals);
}
return true;
}
int ResidualBlock::NumScratchDoublesForEvaluate() const {
// Compute the amount of scratch space needed to store the full-sized
// jacobians. For parameters that have no local parameterization no storage
// is needed and the passed-in jacobian array is used directly. Also include
// space to store the residuals, which is needed for cost-only evaluations.
// This is slightly pessimistic, since both won't be needed all the time, but
// the amount of excess should not cause problems for the caller.
int num_parameters = NumParameterBlocks();
int scratch_doubles = 1;
for (int i = 0; i < num_parameters; ++i) {
const ParameterBlock* parameter_block = parameter_blocks_[i];
if (!parameter_block->IsConstant() &&
parameter_block->LocalParameterizationJacobian() != NULL) {
scratch_doubles += parameter_block->Size();
}
}
scratch_doubles *= NumResiduals();
return scratch_doubles;
}
} // namespace internal
} // namespace ceres