function [ANdata,vFreq] = zilany2007(stim_level,stim,fsstim,fsmod,varargin)
% zilany2007  Humanized auditory nerve model
%   Usage: [ANdata,vFreq] = zilany2007(lvl,stim,fsstim,fsmod);
%
%   Input parameters:
%     stim_level  : Level of stimulus in peSPL
%     stim        : Pressure waveform of stimulus (timeseries)
%     fsstim      : Sampling frequency of stimulus  
%     fsmod       : Model sampling frequency (often 200kHz)
%
%   Output parameters:
%     ANdata     : AN exicitation in 500 different AN fibers spaced equally
%                   on the BM
%     vFreq      : Frequency vector containing the 500 center frequencies
%
%   ZILANY2007(stim_lvl, stim, fsstim, fsmod) returns simulations
%   from Rønne et al. (2012). It calls the mex'ed C code containing the
%   humanized version of Zilany et al. (2007)'s AN model. The humanization
%   is described in Rønne et al. (2012). The AN model is called 500 times to
%   simulate 500 fibers tuned to different center frequencies.
%
%   Please cite Rønne et al (2012) and Zilany and Bruce (2007) if you use
%   this model.
%
%   This function takes the following optional parameters:
%
%     'flow',flow     Lowest centre frequency. Default value is 100.
%
%     'fhigh',fhigh   Highest centre frequency. Default value is 16000.
%
%     'nfibers',nf    Number of fibers between lowest and highest
%                     frequency. The fibers will be equidistantly spaced
%                     on the basilar membrane. Default value is 500.
%  
%   Requirements and installation:
%   ------------------------------
%
%   1) Compiled mex files (run amt_mex)
%   
%   References:
%     F. M. Rønne, T. Dau, J. Harte, and C. Elberling. Modeling auditory
%     evoked brainstem responses to transient stimuli. The Journal of the
%     Acoustical Society of America, 131(5):3903--3913, 2012. [1]http ]
%     
%     M. S. A. Zilany and I. C. Bruce. Representation of the vowel (epsilon)
%     in normal and impaired auditory nerve fibers: Model predictions of
%     responses in cats. J. Acoust. Soc. Am., 122(1):402--417, jul 2007.
%     
%     References
%     
%     1. http://scitation.aip.org/content/asa/journal/jasa/131/5/10.1121/1.3699171
%     
%
%   Url: http://amtoolbox.sourceforge.net/data/amt-test/htdocs/amt-0.10.0/doc/models/zilany2007.php

% Copyright (C) 2009-2020 Piotr Majdak and the AMT team.
% This file is part of Auditory Modeling Toolbox (AMT) version 0.10.0
%
% This program is free software: you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program.  If not, see <http://www.gnu.org/licenses/>.

if nargin<4
  error('%s: Too few input parameters.',upper(mfilename));
end;

% Define input flags
definput.keyvals.flow    = 100;
definput.keyvals.fhigh   = 16000;
definput.keyvals.nfibers = 500;
[flags,kv]  = ltfatarghelper({'flow','fhigh','nfibers'},definput,varargin);

stim	= resample(stim,fsmod,fsstim);	% stim fs = mod fs
idnz	= stim ~= 0;                    % ignore pauses
lvlref = 20*log10(1/20e-6);           % Reference level: 20 micro Pa
stim(idnz) = setdbspl(stim(idnz),stim_level,'dboffset',lvlref); % Calibrate level

% stim must be a row vector
if size(stim,2) == 1
    stim = stim';
end

% location of lowest and highest centre frequency
xlo     = (1.0/0.06)*log10((kv.flow/165.4)+0.88);
xhi     = (1.0/0.06)*log10((kv.fhigh/165.4)+0.88);	

% equal spaced distances on the BM
vX      = linspace(xlo,xhi,kv.nfibers);

% and the resulting frequency vector
vFreq   = 165.4*(10.^(0.06*vX)-0.88); 

% resolution in the time domain
tdres   = 1/fsmod;                

% spontaneous rate in sp/sec
spont   = 50;    

% time in sec between stimulus repetitions - NOTE should be equal to or
% longer than the duration of the stimulus
reptime   = (2*length(stim)+1)/fsmod; 

% cohc is the ohc scaling factor: 1 is normal OHC function; 0 is complete
% OHC dysfunction
cohc    = 1;                                        

% cihc is the ihc scaling factor: 1 is normal IHC function; 0 is complete
% IHC dysfunction
cihc    = 1;                                        

% Call AN model - loop over the 500 fibers tuned to different CFs
for jj = 1:kv.nfibers
  % Call AN model (mex'ed C model)
  [timeout,meout,c1filterout,c2filterout,c1vihc,c2vihc,vihc,synout,psth500k] ...
      = comp_zilany2007(stim,...
                                 vFreq(jj),...
                                 1,...
                                 tdres,...
                                 reptime,...
                                 cohc, ...
                                 cihc,...
                                 spont); 
  
  % Use the output of the synapse stage of the AN model. 
  ANdata(jj,:)           = synout;             
end