annotate carfac/agc_params.cc @ 611:0fbaf443ec82

Carfac C++ revision 3, indluding more style improvements. The output structs are now classes again, and have separate storage methods for each output structure along with flags in the Run and RunSegment methods to allow for only storing NAPs if desired.

//
//  agc_params.cc
//  CARFAC Open Source C++ Library
//
//  Created by Alex Brandmeyer on 5/10/13.
//
// This C++ file is part of an implementation of Lyon's cochlear model:
// "Cascade of Asymmetric Resonators with Fast-Acting Compression"
// to supplement Lyon's upcoming book "Human and Machine Hearing"
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "agc_params.h"

// The default constructor for AGCParams initializes with the settings from
// Lyon's book 'Human and Machine Hearing'
AGCParams::AGCParams() {
  n_stages_ = 4;
  agc_stage_gain_ = 2;
  FPType agc2_factor = 1.65;
  std::vector<FPType> stage_values = {1.0, 1.4, 2.0, 2.8};
  time_constants_.resize(n_stages_);
  agc1_scales_.resize(n_stages_);
  agc2_scales_.resize(n_stages_);
  for (int i = 0; i < n_stages_; ++i) {
    time_constants_(i) = pow(4, i) * 0.002;
    agc1_scales_(i) = stage_values.at(i);
    agc2_scales_(i) = stage_values.at(i) * agc2_factor;
  }
  decimation_ = {8, 2, 2, 2};
  agc_mix_coeff_ = 0.5;
}

// The overloaded constructor allows for use of different AGC parameters.
AGCParams::AGCParams(int n_stages, FPType agc_stage_gain, FPType agc_mix_coeff,
                    FloatArray time_constants, std::vector<int> decimation,
                    FloatArray agc1_scales, FloatArray agc2_scales) {
  n_stages_ = n_stages;
  agc_stage_gain_ = agc_stage_gain;
  agc_mix_coeff_ = agc_mix_coeff;
  time_constants_ = time_constants;
  decimation_ = decimation;
  agc1_scales_ = agc1_scales;
  agc2_scales_ = agc2_scales;
}