annotate branches/carfac_cpp/src/CAR.cpp @ 695:2e3672df5698

Simple integration test between CARFAC and SAI.

The interface between the two classes is pretty clunky because of the
way CARFACOutput stores things.  We should work on this, probably by
rotating the outer two dimensions of CARFACOutput (i.e. store outputs
in containers with sizes n_ears x n_samples x n_channels instead of
n_samples x n_ears x n_channels).

#include "CAR.h"
#include "CARFAC_common.h"
#include "CARFAC.h"
#include <cmath>
#include "unit_conversion.h"

CAR_parameters::CAR_parameters():
	  velocity_scale_(0.2),
	  v_offset_(0.01),
	  v2_corner_(0.2),
	  v_damp_max_(0.01),
	  min_zeta_(0.10),
	  first_pole_theta_(0.085*kPi),
	  zero_ratio_(sqrt(2)),
	  high_f_damping_compression_(0.5),
	  erb_per_step_(0.5),
	  min_pole_hz_(30),
	  erb_break_freq_(kDefaultErbBreakFreq),
	  erb_q_(kDefaultErbQ)
{
    // do nothing more!
}

CAR_coefficients::CAR_coefficients(CAR_parameters* car_params_p, float fs,
                                   FloatArray pole_freqs)
{

  float f = pow(car_params_p->zero_ratio_, 2) + 1;

  // TODO: dirty FloatArray initialization.
  r1_coeffs_= pole_freqs;
  a0_coeffs_= pole_freqs;
  c0_coeffs_= pole_freqs;
  h_coeffs_= pole_freqs;
  g0_coeffs_= pole_freqs;
  zr_coeffs_= pole_freqs;

  FloatArray theta = pole_freqs;

  float min_zeta_mod;
  float x;
  float ff = car_params_p->high_f_damping_compression_;

  // TODO: temp loop until we get eigen in  (or we just leave it like this)
  for(float i=0; i<pole_freqs.size(); i++){
      theta[i] *= (2*kPi*fs); // scalar mult.
      c0_coeffs_[i] = sin(theta[i]);
      a0_coeffs_[i] = cos(theta[i]);

      x = theta[i]/kPi;
      zr_coeffs_[i] = kPi * (x - ff * x*x*x);

      min_zeta_mod = (car_params_p->min_zeta_ + 0.25 * (ERB_Hz(
                      pole_freqs[i], car_params_p->erb_break_freq_,
                      car_params_p->erb_q_) / pole_freqs[i]
                     - car_params_p->min_zeta_));

      r1_coeffs_[i] = 1-zr_coeffs_[i]*min_zeta_mod;

      h_coeffs_[i] = c0_coeffs_[i] * f;

      //TODO: g0_coeffs_ calculated here for now. Let's talk about this, need
      // to see the whole picture of what makes sense.
      // Related: I believe CAR, IHC and AGC classes would be beneficial!
      float tmp = 1 - 2*r1_coeffs_[i]*a0_coeffs_[i] + r1_coeffs_[i]*r1_coeffs_[i];
      g0_coeffs_[i] = tmp / ( tmp + h_coeffs_[i]*r1_coeffs_[i]*c0_coeffs_[i]);
  }

}