GNU Radio 3.6.2 C++ API
gr::filter::iir_filter_ffd Class Reference

IIR filter with float input, float output and double tapsThis filter uses the Direct Form I implementation, where fftaps contains the feed-forward taps, and fbtaps the feedback ones. More...

#include <iir_filter_ffd.h>

Inheritance diagram for gr::filter::iir_filter_ffd:

Public Types

typedef boost::shared_ptr
< iir_filter_ffd
sptr

Public Member Functions

virtual void set_taps (const std::vector< double > &fftaps, const std::vector< double > &fbtaps)=0
- Public Member Functions inherited from gr_sync_block
virtual int work (int noutput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)=0
 just like gr_block::general_work, only this arranges to call consume_each for you
void forecast (int noutput_items, gr_vector_int &ninput_items_required)
 Estimate input requirements given output request.
int general_work (int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
 compute output items from input items
int fixed_rate_ninput_to_noutput (int ninput)
 Given ninput samples, return number of output samples that will be produced. N.B. this is only defined if fixed_rate returns true. Generally speaking, you don't need to override this.
int fixed_rate_noutput_to_ninput (int noutput)
 Given noutput samples, return number of input samples required to produce noutput. N.B. this is only defined if fixed_rate returns true. Generally speaking, you don't need to override this.
- Public Member Functions inherited from gr_block
virtual ~gr_block ()
unsigned history () const
void set_history (unsigned history)
bool fixed_rate () const
 Return true if this block has a fixed input to output rate.
virtual bool start ()
 Called to enable drivers, etc for i/o devices.
virtual bool stop ()
 Called to disable drivers, etc for i/o devices.
void set_output_multiple (int multiple)
 Constrain the noutput_items argument passed to forecast and general_work.
int output_multiple () const
bool output_multiple_set () const
void set_alignment (int multiple)
 Constrains buffers to work on a set item alignment (for SIMD)
int alignment () const
void set_unaligned (int na)
int unaligned () const
void set_is_unaligned (bool u)
bool is_unaligned () const
void consume (int which_input, int how_many_items)
 Tell the scheduler how_many_items of input stream which_input were consumed.
void consume_each (int how_many_items)
 Tell the scheduler how_many_items were consumed on each input stream.
void produce (int which_output, int how_many_items)
 Tell the scheduler how_many_items were produced on output stream which_output.
void set_relative_rate (double relative_rate)
 Set the approximate output rate / input rate.
double relative_rate () const
 return the approximate output rate / input rate
uint64_t nitems_read (unsigned int which_input)
 Return the number of items read on input stream which_input.
uint64_t nitems_written (unsigned int which_output)
 Return the number of items written on output stream which_output.
tag_propagation_policy_t tag_propagation_policy ()
 Asks for the policy used by the scheduler to moved tags downstream.
void set_tag_propagation_policy (tag_propagation_policy_t p)
 Set the policy by the scheduler to determine how tags are moved downstream.
gr_block_detail_sptr detail () const
void set_detail (gr_block_detail_sptr detail)
- Public Member Functions inherited from gr_basic_block
virtual ~gr_basic_block ()
long unique_id () const
std::string name () const
gr_io_signature_sptr input_signature () const
gr_io_signature_sptr output_signature () const
gr_basic_block_sptr to_basic_block ()
virtual bool check_topology (int ninputs, int noutputs)
 Confirm that ninputs and noutputs is an acceptable combination.
template<typename T >
void set_msg_handler (T msg_handler)
 Set the callback that is fired when messages are available.
- Public Member Functions inherited from gr_msg_accepter
 gr_msg_accepter ()
 ~gr_msg_accepter ()
void post (pmt::pmt_t msg)
 send msg to msg_accepter
- Public Member Functions inherited from gruel::msg_accepter
 msg_accepter ()
virtual ~msg_accepter ()

Static Public Member Functions

static sptr make (const std::vector< double > &fftaps, const std::vector< double > &fbtaps)

Additional Inherited Members

- Protected Types inherited from gr_basic_block
enum  vcolor { WHITE, GREY, BLACK }
- Protected Member Functions inherited from gr_sync_block
 gr_sync_block (void)
 gr_sync_block (const std::string &name, gr_io_signature_sptr input_signature, gr_io_signature_sptr output_signature)
- Protected Attributes inherited from gr_basic_block
std::string d_name
gr_io_signature_sptr d_input_signature
gr_io_signature_sptr d_output_signature
long d_unique_id
vcolor d_color

Detailed Description

IIR filter with float input, float output and double taps

This filter uses the Direct Form I implementation, where fftaps contains the feed-forward taps, and fbtaps the feedback ones.

The input and output satisfy a difference equation of the form \f{ y[n] - \sum_{k=1}^{M} a_k y[n-k] = \sum_{k=0}^{N} b_k x[n-k] \f}

with the corresponding rational system function \f{ H(z) = \ frac{\sum_{k=0}^{M} b_k z^{-k}}{1 - \sum_{k=1}^{N} a_k z^{-k}} \f}

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.

Member Typedef Documentation

Member Function Documentation

static sptr gr::filter::iir_filter_ffd::make ( const std::vector< double > &  fftaps,
const std::vector< double > &  fbtaps 
)
static
virtual void gr::filter::iir_filter_ffd::set_taps ( const std::vector< double > &  fftaps,
const std::vector< double > &  fbtaps 
)
pure virtual

The documentation for this class was generated from the following file: