text: /*=========================================================================
   *
   *  Copyright Insight Software Consortium
   *
   *  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
   *
   *         http://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 itkSingleValuedCostFunction_h
  #define itkSingleValuedCostFunction_h
  
  #include "itkCostFunction.h"
  #include "itkNumericTraits.h"
  
  namespace itk
  {
  /** \class SingleValuedCostFunction
   * \brief This class is a base for the CostFunctions returning a
   * single value
   *
   * \ingroup Numerics Optimizers
   * \ingroup ITKOptimizers
   */
  class SingleValuedCostFunction:
    public CostFunction
  {
  public:
    /** Standard class typedefs. */
    typedef SingleValuedCostFunction   Self;
    typedef CostFunction               Superclass;
    typedef SmartPointer< Self >       Pointer;
    typedef SmartPointer< const Self > ConstPointer;
  
    /** Run-time type information (and related methods). */
    itkTypeMacro(SingleValuedCostFunction, CostFunction);
  
    /**  MeasureType typedef.
     *  It defines a type used to return the cost function value. */
    typedef double MeasureType;
  
    /**  ParametersType typedef.
     *  It defines a position in the optimization search space. */
    typedef Superclass::ParametersType      ParametersType;
    typedef Superclass::ParametersValueType ParametersValueType;
  
    /** DerivativeType typedef.
     *  It defines a type used to return the cost function derivative.  */
    typedef Array< ParametersValueType > DerivativeType;
  
    /** This method returns the value of the cost function corresponding
      * to the specified parameters.    */
    virtual MeasureType GetValue(const ParametersType & parameters) const = 0;
  
    /** This method returns the derivative of the cost function corresponding
      * to the specified parameters.   */
    virtual void GetDerivative(const ParametersType & parameters,
                               DerivativeType & derivative) const = 0;
  
    /** This method returns the value and derivative of the cost function corresponding
      * to the specified parameters    */
    virtual void GetValueAndDerivative(const ParametersType & parameters,
                                       MeasureType & value,
                                       DerivativeType & derivative) const
    {
      value = this->GetValue(parameters);
      this->GetDerivative(parameters, derivative);
    }
  
  protected:
    SingleValuedCostFunction() {}
    virtual ~SingleValuedCostFunction() {}
  
  private:
    SingleValuedCostFunction(const Self &); //purposely not implemented
    void operator=(const Self &);           //purposely not implemented
  };
  } // end namespace itk
  
  #endif
  