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#ifndef _GR_SINGLE_POLE_IIR_H_
00023
#define _GR_SINGLE_POLE_IIR_H_
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00025
#include <stdexcept>
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00030
template<
class o_type,
class i_type,
class tap_type>
00031 class gr_single_pole_iir {
00032
public:
00038 gr_single_pole_iir (
tap_type alpha = 1.0)
00039 {
00040 d_prev_output = 0;
00041
set_taps (alpha);
00042 }
00043
00048
o_type filter (
const i_type input);
00049
00054
void filterN (
o_type output[],
const i_type input[],
unsigned long n);
00055
00059 void set_taps (
tap_type alpha)
00060 {
00061
if (alpha < 0 || alpha > 1)
00062
throw std::out_of_range (
"Alpha must be in [0, 1]\n");
00063
00064 d_alpha = alpha;
00065 d_one_minus_alpha = 1.0 - alpha;
00066 }
00067
00069 void reset ()
00070 {
00071 d_prev_output = 0;
00072 }
00073
00074
protected:
00075 tap_type d_alpha;
00076 tap_type d_one_minus_alpha;
00077 tap_type d_prev_output;
00078 };
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template<
class o_type,
class i_type,
class tap_type>
00085
o_type
00086 gr_single_pole_iir<o_type, i_type, tap_type>::filter (
const i_type input)
00087 {
00088
tap_type output;
00089
00090 output =
d_alpha * input +
d_one_minus_alpha *
d_prev_output;
00091 d_prev_output = output;
00092
00093
return (
o_type) output;
00094 }
00095
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00097
template<
class o_type,
class i_type,
class tap_type>
00098
void
00099 gr_single_pole_iir<o_type, i_type, tap_type>::filterN (
o_type output[],
00100
const i_type input[],
00101
unsigned long n)
00102 {
00103
for (
unsigned i = 0; i < n; i++)
00104 output[i] =
filter (input[i]);
00105 }
00106
00107
00108
#endif