[Insight-users] Re: LevenbergMarquardt Optimizer & Derivatives

[Mark Hastenteufel]

Hi Luis,

thanks for your quick modifications. Did you checked in the new Code?
I've just checked out the toolkit but the I could not found your
modifications.


Mark



Luis Ibanez schrieb:
> 
> Hi Mark,
> 
> The modifications to the LevenbergMarquardt
> optimizer that you suggested have been made.
> 
> Here is a summary of the changes:
> 
> 1) In  itkMultipleValuedVnlCostFunctionAdaptor
> 
>    the following methods were added:
> 
>    void SetUseGradient(bool);
>    void UseGradientOn();
>    void UseGradientOff();
>    bool GetUseGradient();
> 
>    They map to the use_gradient member variable
>    of the vnl_least_squares_function class
> 
> 2) In the itkLevenbergMarquardtOptimizer
> 
>     the following methods were added:
> 
>    void SetUseCostFunctionGradient(bool);
>    void UseCostFunctionGradientOn();
>    void UseCostFunctionGradientOff();
>    bool GetUseCostFunctionGradient();
> 
>   These methods provide access to the methods
>   listed in (1) on the VnlAdaptor.
> 
> The usage is illustrated in the file:
> 
> Insight/Testing/Code/Numerics/itkLevenbergMarquardOptimizerTest.cxx
> 
> basically:
> 
>    Optimizer->SetCostFunction( costFunction.GetPointer() );
> 
>    and the use of the gradient can be enabled by any of
>    the following calls:
> 
>    costFunction->SetUseGradient( true );
> 
>    Optimizer->SetUseCostFunctionGradient( useGradient );
> 
> The last one requires the CostFuction to be already
> plugged into the optimizer.
> 
> Please let us know if you find any problem
> with the current implementation.
> 
>    Thanks
> 
>     Luis

-- 
Mark Hastenteufel
Deutsches Krebsforschungszentrum         (German Cancer Research Center)
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