view trunk/carfac/agc_params.h @ 679:594b410c2aed

Sixth revision of Alex Brandmeyer's C++ implementation. Only small changes in response to Lyon's comments from r285. Note: I tried to use a consistent indentation with two spaces, but also preserving parenthetical structure to make reading the longer equations easier. Please advise if this is OK. Additional documentation and tests with non-standard parameter sets will be added in a subsequent revision.

//
//  agc_params.h
//  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.

#ifndef CARFAC_Open_Source_C__Library_AGCParams_h
#define CARFAC_Open_Source_C__Library_AGCParams_h

#include "carfac_common.h"

struct AGCParams {
  AGCParams() {
    n_stages_ = 4;
    agc_stage_gain_ = 2.0;
    time_constants_.resize(n_stages_);
    agc1_scales_.resize(n_stages_);
    agc2_scales_.resize(n_stages_);
    agc1_scales_[0] = 1.0;
    agc2_scales_[0] = 1.65;
    time_constants_[0] = 0.002;
    for (int i = 1; i < n_stages_; ++i) {
      agc1_scales_[i] = agc1_scales_[i - 1] * sqrt(2.0);
      agc2_scales_[i] = agc2_scales_[i - 1] * sqrt(2.0);
      time_constants_[i] = time_constants_[i - 1] * 4.0;
    }
    decimation_ = {8, 2, 2, 2};
    agc_mix_coeff_ = 0.5;
  }
  int n_stages_;
  FPType agc_stage_gain_;
  FPType agc_mix_coeff_;
  std::vector<FPType> time_constants_;
  std::vector<int> decimation_;
  std::vector<FPType> agc1_scales_;
  std::vector<FPType> agc2_scales_;
};

#endif