fir_iir.cpp

Output

  Filter coeffs:
  -0.0051   0.0134   0.1474   0.3444   0.3444   0.1474   0.0134  -0.0051
  Impulse response:
  -0.0051   0.0134   0.1474   0.3444   0.3444   0.1474   0.0134  -0.0051 0 0 0
*0        0        0        0
 
  IIR theor. impulse response:
  0.2500   0.7250   0.9025   0.8123   0.7310   0.6579   0.5921   0.5329 0.4796
*0.4317   0.3885 ... IIR output: 0.2500   0.7250   0.9025   0.8123   0.7310
*0.6579   0.5921   0.5329   0.4796   0.4317   0.3885   0.3496   0.3147   0.2832
*0.2549
 
  Delay three samples:
    0        0        0   0.2500   0.7250   0.9025   0.8123   0.7310   0.6579
*0.5921   0.5329   0.4796   0.4317   0.3885   0.3496

Source

 
#include "sigpack.h"
 
using namespace arma;
using namespace sp;
 
int main()
{
    // Filter coeffs.
    vec b;
    int N = 15;
 
    // Create a FIR filter
    FIR_filt<double, double, double> fir_filt;
    b = fir1( 7, 0.35 );
    fir_filt.set_coeffs( b );
 
    vec X( N ); // Input sig
    X.zeros();
    X[0] = 1; // Impulse
 
    vec Y( N ); // Output sig
    Y.zeros();
 
    // Filter - sample loop
    for( int n = 0; n < N; n++ )
    {
        Y[n] = fir_filt( X[n] );
    }
 
    std::cout << "Filter coeffs: \n" << b.t() << std::endl;
    std::cout << "Impulse response:\n" << Y.t() << std::endl;
 
    // Create a IIR filter
    IIR_filt<double, double, double> iir_filt;
    vec                              a;
    b = { 0.25, 0.5, 0.25 };
    a = { 1, -0.9 };
 
    iir_filt.set_coeffs( b, a );
    Y = iir_filt.filter( X );
    std::cout << "IIR theor. impulse response: \n   0.2500   0.7250   0.9025   0.8123  "
                 " 0.7310   0.6579   0.5921   0.5329   0.4796   0.4317   0.3885 ..."
              << std::endl;
    std::cout << "IIR output: \n" << Y.t() << std::endl;
 
    Delay<double> del( 3 );
    std::cout << "Delay three samples:\n" << del.delay( Y ).t() << std::endl;
 
    return 0;
}