AdaptiveFilter.h

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#ifndef ADAPTIVEFILTER_H
#define ADAPTIVEFILTER_H

/** \addtogroup sigproc Signal processing methods */
/* @{ */

/*!
 * \file Basic class for adaptive filtering of time series data
 * \author Max Moorkamp
 * $Id: $
 * 
 * The class AdaptiveFilter provides the generic interface for all types of adaptive Filters
 */

#include "types.h"
#include "VecMat.h"
namespace ublas = boost::numeric::ublas;
//! A generic base class for all types of adaptive filters
/*! The class AdaptiveFilter provides a unified interface for various types
 * of adaptive filters and storage for some quantities that are common to all
 * of them. Ideally this should facilitate transparent use of all filters in 
 * any program or routine. See, for example, mtuadaptive.cpp. We assume that the filter length
 * and number of output points is constant for the life of the object.
 */
class AdaptiveFilter{
private:
    //! The vector holding the last filter output calculated
        gplib::rvec FilterOutput;
        //! The vector holding the last estimation error
        gplib::rvec Epsilon;
        //! length of the input vector to the filter, this is not the time-series length, but the segment the filter operates on
        const unsigned int inputlength;
        //! length of the filter output
        const unsigned int outputlength;
protected:
        //! Access function for derived classes for the inputlength
        unsigned int GetInputLength(){return inputlength;}
        //! Access function for derived classes for the outputlength
        unsigned int GetOutputLength(){return outputlength;}
        //! Possibility for derived classes to set estimation error
    void SetEpsilon(const gplib::rvec &MyEps){Epsilon=MyEps;}
    //! Possibility for derived classes to set output
    void SetOutput(const gplib::rvec &Out){FilterOutput = Out;}
public:
        //! Access to the last calculated output (not sure if needed)
        const gplib::rvec &GetFilterOutput() const {return FilterOutput;}
        //! Return the last estimation error
        const gplib::rvec &GetEpsilon() const {return Epsilon;}
        //! Print the current set of weights to the output stream, has to be implemented in derived class 
        virtual void PrintWeights(std::ostream &output) =0;
        //! We can always convert the weights to some sort of vector, the details have to be implemented in the derived class
        virtual const gplib::rvec &GetWeightsAsVector() = 0;
        //! Adapt the filter weights given the Input and Desired vectors
        virtual void AdaptFilter(const gplib::rvec &Input, const gplib::rvec &Desired) = 0;
        //! Calculate the filter output given Input
        virtual void CalcOutput(const gplib::rvec &Input, gplib::rvec &Output) = 0;
        //! The constructor needs to know the length of the input and output vectors for memory allocation
        AdaptiveFilter(const int inputsize, const int outputsize);
        virtual ~AdaptiveFilter();
        friend class ApplyFilter;
};
/* @} */
#endif // ADAPTIVEFILTER_H

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