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 << endr;
  a << 1.0 << -0.9 << endr;

  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;
}