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23 #ifndef INCLUDED_GR_SINGLE_POLE_REC_FILTER_FF_H
24 #define INCLUDED_GR_SINGLE_POLE_REC_FILTER_FF_H
26 #include <gr_sync_block.h>
27 #include <gr_single_pole_avg.h>
30 class gr_single_pole_avg_filter_ff;
31 typedef boost::shared_ptr<gr_single_pole_avg_filter_ff> gr_single_pole_avg_filter_ff_sptr;
33 gr_single_pole_avg_filter_ff_sptr
34 gr_make_single_pole_avg_filter_ff (double alpha, unsigned int vlen=1);
37 * \brief single pole moving average filter with float input, float output
40 * The input and output satisfy a difference equation of the form
43 y[n] - (1-alpha) y[n-1] = alpha x[n]
46 * with the corresponding rational system function
49 H(z) = \frac{alpha}{1 - (1-alpha) z^{-1}}
52 * Note that some texts define the system function with a + in the denominator.
53 * If you're using that convention, you'll need to negate the feedback tap.
55 class gr_single_pole_avg_filter_ff : public gr_sync_block
58 friend gr_single_pole_avg_filter_ff_sptr
59 gr_make_single_pole_avg_filter_ff (double alpha, unsigned int vlen);
62 std::vector<gr_single_pole_avg<float,float,double> > d_rec;
64 gr_single_pole_avg_filter_ff (double alpha, unsigned int vlen);
67 ~gr_single_pole_avg_filter_ff ();
69 void set_taps (double alpha);
71 int work (int noutput_items,
72 gr_vector_const_void_star &input_items,
73 gr_vector_void_star &output_items);