#ifndef __DIGITAL_FILTER__
#define __DIGITAL_FILTER__

/**
 * 
 * デジタルフィルタを表現したクラス
 * FIRとIIRを実装してみる
 */


class DigitalFilter{
  public:
    template <class IterInput, class IterCoef>
    static typename IterInput::value_type fir(
        IterInput input_iter, IterCoef coef_begin, const IterCoef coef_end){
      typename IterInput::value_type res(0);
      for(; coef_begin != coef_end; ++coef_begin, ++input_iter){
        res += (*input_iter) * (*coef_begin);
      }
      return res;
    }
    template <class InputT, class IterCoef>
    static InputT fir(
        InputT *input_iter, IterCoef coef_begin, const IterCoef coef_end){
      InputT res(0);
      for(; coef_begin != coef_end; ++coef_begin, ++input_iter){
        res += (*input_iter) * (*coef_begin);
      }
      return res;
    }
    template <class IterT, class IterCoef>
    static typename IterT::value_type iir(
        IterT input_iter, IterCoef coef_in_begin, const IterCoef coef_in_end,
        IterT output_iter, IterCoef coef_out_begin, const IterCoef coef_out_end){
      typename IterT::value_type res(0);
      for(; coef_in_begin != coef_in_end; ++coef_in_begin, ++input_iter){
        res += (*input_iter) * (*coef_in_begin);
      }
      for(; coef_out_begin != coef_out_end; ++coef_out_begin, ++output_iter){
        res += (*output_iter) * (*coef_out_begin);
      }
      return res;
    }
    template <class T, class IterCoef>
    static T iir(
        T *input_iter, IterCoef coef_in_begin, const IterCoef coef_in_end,
        T *output_iter, IterCoef coef_out_begin, const IterCoef coef_out_end){
      T res(0);
      for(; coef_in_begin != coef_in_end; ++coef_in_begin, ++input_iter){
        res += (*input_iter) * (*coef_in_begin);
      }
      for(; coef_out_begin != coef_out_end; ++coef_out_begin, ++output_iter){
        res += (*output_iter) * (*coef_out_begin);
      }
      return res;
    }
};


#endif /* __DIGITAL_FILTER__ */