gr::filter::kernel::iir_filter< i_type, o_type, tap_type > Class Template Reference
base class template for Infinite Impulse Response filter (IIR) More...
#include <iir_filter.h>
Public Member Functions | |
| iir_filter (const std::vector< tap_type > &fftaps, const std::vector< tap_type > &fbtaps) throw (std::invalid_argument) | |
| Construct an IIR with the given taps. | |
| iir_filter () | |
| ~iir_filter () | |
| o_type | filter (const i_type input) |
| compute a single output value. | |
| void | filter_n (o_type output[], const i_type input[], long n) |
compute an array of N output values. input must have N valid entries. | |
| unsigned | ntaps_ff () const |
| unsigned | ntaps_fb () const |
| void | set_taps (const std::vector< tap_type > &fftaps, const std::vector< tap_type > &fbtaps) throw (std::invalid_argument) |
| install new taps. | |
Protected Attributes | |
| std::vector< tap_type > | d_fftaps |
| std::vector< tap_type > | d_fbtaps |
| int | d_latest_n |
| int | d_latest_m |
| std::vector< tap_type > | d_prev_output |
| std::vector< i_type > | d_prev_input |
Detailed Description
template<class i_type, class o_type, class tap_type>
class gr::filter::kernel::iir_filter< i_type, o_type, tap_type >
base class template for Infinite Impulse Response filter (IIR)
Constructor & Destructor Documentation
template<class i_type, class o_type, class tap_type>
| gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::iir_filter | ( | const std::vector< tap_type > & | fftaps, |
| const std::vector< tap_type > & | fbtaps | ||
| ) | throw (std::invalid_argument) [inline] |
Construct an IIR with the given taps.
This filter uses the Direct Form I implementation, where fftaps contains the feed-forward taps, and fbtaps the feedback ones.
fftaps and fbtaps must have equal numbers of taps
The input and output satisfy a difference equation of the form
![\[ y[n] - \sum_{k=1}^{M} a_k y[n-k] = \sum_{k=0}^{N} b_k x[n-k] \]](form_0.png)
with the corresponding rational system function
![\[ H(z) = \frac{\sum_{k=0}^{N} b_k z^{-k}}{1 - \sum_{k=1}^{M} a_k z^{-k}} \]](form_1.png)
Note that some texts define the system function with a + in the denominator. If you're using that convention, you'll need to negate the feedback taps.
template<class i_type, class o_type, class tap_type>
| gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::iir_filter | ( | ) | [inline] |
template<class i_type, class o_type, class tap_type>
| gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::~iir_filter | ( | ) | [inline] |
Member Function Documentation
template<class i_type, class o_type , class tap_type >
| o_type gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::filter | ( | const i_type | input | ) |
compute a single output value.
- Returns:
- the filtered input value.
template<class i_type, class o_type, class tap_type >
| void gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::filter_n | ( | o_type | output[], |
| const i_type | input[], | ||
| long | n | ||
| ) |
compute an array of N output values. input must have N valid entries.
template<class i_type, class o_type, class tap_type>
| unsigned gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::ntaps_fb | ( | ) | const [inline] |
template<class i_type, class o_type, class tap_type>
| unsigned gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::ntaps_ff | ( | ) | const [inline] |
- Returns:
- number of taps in filter.
template<class i_type, class o_type, class tap_type>
| void gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::set_taps | ( | const std::vector< tap_type > & | fftaps, |
| const std::vector< tap_type > & | fbtaps | ||
| ) | throw (std::invalid_argument) [inline] |
install new taps.
Referenced by gr::filter::kernel::iir_filter< float, float, double >::iir_filter().
Member Data Documentation
template<class i_type, class o_type, class tap_type>
std::vector<tap_type> gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::d_fbtaps [protected] |
template<class i_type, class o_type, class tap_type>
std::vector<tap_type> gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::d_fftaps [protected] |
template<class i_type, class o_type, class tap_type>
int gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::d_latest_m [protected] |
template<class i_type, class o_type, class tap_type>
int gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::d_latest_n [protected] |
template<class i_type, class o_type, class tap_type>
std::vector<i_type> gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::d_prev_input [protected] |
template<class i_type, class o_type, class tap_type>
std::vector<tap_type> gr::filter::kernel::iir_filter< i_type, o_type, tap_type >::d_prev_output [protected] |
The documentation for this class was generated from the following file:
