source: trunk/lib/svm/Kernel_MEV.h @ 307

// $Id: Kernel_MEV.h 307 2005-05-03 13:28:29Z peter $

#ifndef _theplu_svm_kernel_mev
#define _theplu_svm_kernel_mev

#include <c++_tools/gslapi/matrix.h>

namespace theplu {
namespace svm {

  class KernelFunction;

  ///
  ///   Class taking care of the \f$NxN\f$ kernel matrix, where
  ///   \f$N\f$ is number of samples. Type of Kernel is defined by a
  ///   KernelFunction. This Memory Efficient Versions (SEV) does not
  ///   store the kernel matrix in memory, but calculates each element
  ///   when it is needed.
  ///   
  ///   @see also Kernel_SEV
  ///
  class Kernel_MEV 
  {
    
  public:
    
    Kernel_MEV();

    ///
    ///   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_MEV(const gslapi::matrix&, const KernelFunction&);
    
    ///
    ///   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.
    ///   @todo
    Kernel_MEV(const gslapi::matrix& data, const KernelFunction&, 
               const gslapi::matrix& weight);

    ///
    ///   Destructor
    ///
    virtual ~Kernel_MEV(void);

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

    ///
    /// @brief number of samples
    ///
    inline size_t size(void) const { return data_.columns(); }
    
  protected:
    const gslapi::matrix& data_;
    const KernelFunction* kf_;

  }; // class Kernel_MEV

}} // of namespace svm and namespace theplu

#endif