source: trunk/lib/svm/Kernel.h @ 350

// $Id: Kernel.h 350 2005-06-08 19:19:51Z peter $

#ifndef _theplu_svm_kernel_
#define _theplu_svm_kernel_

#include <cctype>

namespace theplu {

namespace gslapi {
  class matrix;
}

namespace svm {

  class KernelFunction;

  ///
  ///   @brief Base Class for Kernels. 
  ///
  ///   Class taking care of the \f$NxN\f$ kernel matrix, where
  ///   \f$N\f$ is number of samples. Each element in the Kernel
  ///   matrix is the scalar product of the corresponding pair of
  ///   samples. Type of Kernel is defined by a KernelFunction.
  ///   
  ///   @note If the KernelFunction is destroyed, the Kernel is no
  ///   longer defined.
  ///
  class Kernel
  {
    
  public:

    ///
    /// Default constructor
    ///
    Kernel(void) {};

    ///
    /// Copy constructor (not implemented)
    ///
    Kernel(const Kernel&);

    ///
    ///   Constructor taking the data matrix and KernelFunction as
    ///   input.Each column in the data matrix corresponds to one
    ///   sample. @note Can not handle NaNs. 
    ///
    Kernel(const gslapi::matrix&, const KernelFunction&) {};
    
    ///
    ///   @todo Constructor taking the \a data matrix, the KernelFunction and a
    ///   \a weight matrix as input. Each column in the data matrix
    ///   corresponds to one sample.
    Kernel(const gslapi::matrix& data, const KernelFunction&, 
           const gslapi::matrix& weight);

    ///
    ///   Destructor
    ///
    virtual ~Kernel(void) {};

    ///
    /// @return element at position (\a row, \a column) of the Kernel
    /// matrix
    ///
    virtual double operator()(const size_t row,const size_t column) const=0;

    ///
    /// @brief number of samples
    ///
    virtual size_t size(void) const=0;
    
  protected:

  }; // class Kernel

}} // of namespace svm and namespace theplu

#endif