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/*=========================================================================
*
* Copyright NumFOCUS
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
#ifndef itkMultiGradientOptimizerv4_hxx
#define itkMultiGradientOptimizerv4_hxx
#include "itkPrintHelper.h"
namespace itk
{
template <typename TInternalComputationValueType>
MultiGradientOptimizerv4Template<TInternalComputationValueType>::MultiGradientOptimizerv4Template()
{
this->m_NumberOfIterations = static_cast<SizeValueType>(0);
this->m_StopCondition = StopConditionObjectToObjectOptimizerEnum::MAXIMUM_NUMBER_OF_ITERATIONS;
this->m_StopConditionDescription << this->GetNameOfClass() << ": ";
this->m_MaximumMetricValue = NumericTraits<MeasureType>::max();
this->m_MinimumMetricValue = this->m_MaximumMetricValue;
}
template <typename TInternalComputationValueType>
void
MultiGradientOptimizerv4Template<TInternalComputationValueType>::PrintSelf(std::ostream & os, Indent indent) const
{
using namespace print_helper;
Superclass::PrintSelf(os, indent);
os << indent << "Stop: " << (m_Stop ? "On" : "Off") << std::endl;
os << indent << "StopCondition: " << m_StopCondition << std::endl;
os << indent << "StopConditionDescription: " << m_StopConditionDescription.str() << std::endl;
os << indent << "OptimizersList: " << m_OptimizersList << std::endl;
os << indent << "MetricValuesList: " << m_MetricValuesList << std::endl;
os << indent
<< "MinimumMetricValue: " << static_cast<typename NumericTraits<MeasureType>::PrintType>(m_MinimumMetricValue)
<< std::endl;
os << indent
<< "MaximumMetricValue: " << static_cast<typename NumericTraits<MeasureType>::PrintType>(m_MaximumMetricValue)
<< std::endl;
}
template <typename TInternalComputationValueType>
auto
MultiGradientOptimizerv4Template<TInternalComputationValueType>::GetOptimizersList() -> OptimizersListType &
{
return this->m_OptimizersList;
}
template <typename TInternalComputationValueType>
void
MultiGradientOptimizerv4Template<TInternalComputationValueType>::SetOptimizersList(
typename MultiGradientOptimizerv4Template::OptimizersListType & p)
{
if (p != this->m_OptimizersList)
{
this->m_OptimizersList = p;
this->Modified();
}
}
template <typename TInternalComputationValueType>
auto
MultiGradientOptimizerv4Template<TInternalComputationValueType>::GetMetricValuesList() const
-> const MetricValuesListType &
{
return this->m_MetricValuesList;
}
template <typename TInternalComputationValueType>
auto
MultiGradientOptimizerv4Template<TInternalComputationValueType>::GetStopConditionDescription() const
-> const StopConditionReturnStringType
{
return this->m_StopConditionDescription.str();
}
template <typename TInternalComputationValueType>
void
MultiGradientOptimizerv4Template<TInternalComputationValueType>::StopOptimization()
{
itkDebugMacro("StopOptimization called with a description - " << this->GetStopConditionDescription());
this->m_Stop = true;
// FIXME
// this->m_Metric->SetParameters( this->m_OptimizersList[ this->m_BestParametersIndex ] );
this->InvokeEvent(EndEvent());
}
template <typename TInternalComputationValueType>
void
MultiGradientOptimizerv4Template<TInternalComputationValueType>::StartOptimization(bool doOnlyInitialization)
{
itkDebugMacro("StartOptimization");
auto maxOpt = static_cast<SizeValueType>(this->m_OptimizersList.size());
if (maxOpt == SizeValueType{})
{
itkExceptionMacro(" No optimizers are set.");
}
if (!this->m_Metric)
{
this->m_Metric = this->m_OptimizersList[0]->GetModifiableMetric();
}
this->m_MetricValuesList.clear();
this->m_MinimumMetricValue = this->m_MaximumMetricValue;
const ParametersType & testParamsAreTheSameObject = this->m_OptimizersList[0]->GetCurrentPosition();
this->m_MetricValuesList.push_back(this->m_MaximumMetricValue);
// Initialize the optimizer, but don't run it.
this->m_OptimizersList[0]->StartOptimization(true /* doOnlyInitialization */);
for (SizeValueType whichOptimizer = 1; whichOptimizer < maxOpt; ++whichOptimizer)
{
this->m_MetricValuesList.push_back(this->m_MaximumMetricValue);
const ParametersType & compareParams = this->m_OptimizersList[whichOptimizer]->GetCurrentPosition();
if (&compareParams != &testParamsAreTheSameObject)
{
itkExceptionMacro(" Parameter objects are not identical across all optimizers/metrics.");
}
// Initialize the optimizer, but don't run it.
this->m_OptimizersList[whichOptimizer]->StartOptimization(true /* doOnlyInitialization */);
}
this->m_CurrentIteration = static_cast<SizeValueType>(0);
// Must call the superclass version for basic validation and setup,
// and to start the optimization loop.
if (this->m_NumberOfIterations > static_cast<SizeValueType>(0))
{
Superclass::StartOptimization(doOnlyInitialization);
}
}
template <typename TInternalComputationValueType>
void
MultiGradientOptimizerv4Template<TInternalComputationValueType>::ResumeOptimization()
{
this->m_StopConditionDescription.str("");
this->m_StopConditionDescription << this->GetNameOfClass() << ": ";
this->InvokeEvent(StartEvent());
itkDebugMacro(" start ");
this->m_Stop = false;
while (!this->m_Stop)
{
// Compute metric value/derivative.
auto maxOpt = static_cast<SizeValueType>(this->m_OptimizersList.size());
// We rely on learning rate or parameter scale estimator to do the weighting.
TInternalComputationValueType combinefunction =
NumericTraits<TInternalComputationValueType>::OneValue() / static_cast<TInternalComputationValueType>(maxOpt);
itkDebugMacro(" nopt " << maxOpt);
for (SizeValueType whichOptimizer = 0; whichOptimizer < maxOpt; ++whichOptimizer)
{
this->m_OptimizersList[whichOptimizer]->GetMetric()->GetValueAndDerivative(
const_cast<MeasureType &>(this->m_OptimizersList[whichOptimizer]->GetCurrentMetricValue()),
const_cast<DerivativeType &>(this->m_OptimizersList[whichOptimizer]->GetGradient()));
itkDebugMacro(" got-deriv " << whichOptimizer);
if (this->m_Gradient.Size() != this->m_OptimizersList[whichOptimizer]->GetGradient().Size())
{
this->m_Gradient.SetSize(this->m_OptimizersList[whichOptimizer]->GetGradient().Size());
itkDebugMacro(" resized ");
}
// Modify the gradient by scales, weights and learning rate.
this->m_OptimizersList[whichOptimizer]->ModifyGradientByScales();
this->m_OptimizersList[whichOptimizer]->EstimateLearningRate();
this->m_OptimizersList[whichOptimizer]->ModifyGradientByLearningRate();
itkDebugMacro(" mod-grad ");
// Combine the gradients
if (whichOptimizer == 0)
{
this->m_Gradient.Fill(0);
}
this->m_Gradient = this->m_Gradient + this->m_OptimizersList[whichOptimizer]->GetGradient() * combinefunction;
itkDebugMacro(" add-grad ");
this->m_MetricValuesList[whichOptimizer] = this->m_OptimizersList[whichOptimizer]->GetCurrentMetricValue();
} // end loop
// Check if optimization has been stopped externally.
// (Presumably this could happen from a multi-threaded client app?)
if (this->m_Stop)
{
this->m_StopConditionDescription << "StopOptimization() called";
break;
}
try
{
// Pass combined gradient to transforms and let them update
itkDebugMacro(" combine-grad ");
this->m_OptimizersList[0]->GetModifiableMetric()->UpdateTransformParameters(this->m_Gradient);
}
catch (const ExceptionObject &)
{
this->m_StopCondition = StopConditionObjectToObjectOptimizerEnum::UPDATE_PARAMETERS_ERROR;
this->m_StopConditionDescription << "UpdateTransformParameters error";
this->StopOptimization();
// Pass exception to caller
throw;
}
this->InvokeEvent(IterationEvent());
// Update and check iteration count
this->m_CurrentIteration++;
if (this->m_CurrentIteration >= this->m_NumberOfIterations)
{
this->m_StopConditionDescription << "Maximum number of iterations (" << this->m_NumberOfIterations
<< ") exceeded.";
this->m_StopCondition = StopConditionObjectToObjectOptimizerEnum::MAXIMUM_NUMBER_OF_ITERATIONS;
this->StopOptimization();
break;
}
} // while (!m_Stop)
}
} // namespace itk
#endif
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