tomwalters@0: function  [pdampsmod, agcstate] = AGCdampStep(detect, pdamps, ...
tomwalters@0: 					      agcepsilons, agcgains, agcstate, agcfactor);
tomwalters@0:   % 
tomwalters@0:   
tomwalters@0: % function [pdampsmod, agcstate] = AGCdampStep(detect, pdamps,
tomwalters@0: %                                  agcepsilons, agcgains, agcstate);
tomwalters@0: % 
tomwalters@0: %  update the dampings and agcstates based on present outputs
tomwalters@0: %  including 50% stereo coupling if two channels based on size of
tomwalters@0: %  agcstate is twice the number of channels
tomwalters@0: 
tomwalters@0: if nargin < 6
tomwalters@0:     agcfactor=12;
tomwalters@0: end
tomwalters@0: 
tomwalters@0: Nch = length(pdamps);
tomwalters@0: Ntracks = size(detect,2); % two columns for stereo
tomwalters@0: Nstages = length(agcepsilons);
tomwalters@0: 
tomwalters@0: 
tomwalters@0: if length(detect)==0,
tomwalters@0:   Ntracks = 1; % mono default
tomwalters@0:   if size(agcstate,2)>Nstages
tomwalters@0:     Ntracks = round(size(agcstate,2)/Nstages); % pass in agcstate big
tomwalters@0:                                                 % enough to do stereo
tomwalters@0:   end
tomwalters@0:   detect = DetectFun(0.0)*ones(Nch,1);
tomwalters@0:   %agcstate = 1.2*detect*ones(1,Ntracks*Nstages); % a detect-dependent
tomwalters@0:   %hack to initialize damping
tomwalters@0:   rep = 1+rem((1:Ntracks*Nstages)-1,Nstages);
tomwalters@0:   agcstate = 1.2*detect*agcgains(rep); % rep is like [1 2 3 4 1 2 3 4]
tomwalters@0:   detect = DetectFun(0.0)*ones(Nch,Ntracks);
tomwalters@0: end
tomwalters@0: 
tomwalters@0: agcepsleft = 0.3; % 0.15;
tomwalters@0: agcepsright = 0.3; % 0.15;
tomwalters@0: spacecoeffs = [agcepsleft, 1.0-agcepsleft-agcepsright, agcepsright];
tomwalters@0: 
tomwalters@0: for k = 1:Ntracks % track number (1 for mono, 2 for second channel)
tomwalters@0:   for j = 1:Nstages % stage number
tomwalters@0:     jj = j + (k-1)*Nstages; % index into state columns
tomwalters@0:     %spatial smoothing:
tomwalters@0:     agcavg = filter(spacecoeffs, 1, [agcstate(1,jj); agcstate(:,jj); ...
tomwalters@0: 		    agcstate(Nch,jj)]);
tomwalters@0:     agcavg = agcavg(3:(Nch+2));
tomwalters@0:     %time smoothing:
tomwalters@0:     epsilon = agcepsilons(j);
tomwalters@0:     agcstate(:,jj) = agcavg*(1-epsilon) + epsilon*detect(:,k)*agcgains(j);
tomwalters@0:   end
tomwalters@0: end
tomwalters@0: 
tomwalters@0: %agcstate can't exceed 0.25, usually , with max detect being 0.5
tomwalters@0: % only INCREASE the damping over pdamp
tomwalters@0: %agcfactor = 12; % 6.0; % 12.0;
tomwalters@0: % now set above or as an argument
tomwalters@0: 
tomwalters@0: offset = 1-agcfactor*DetectFun(0.0);  % 0.7422 for DetectFun(0)=0.0215
tomwalters@0: % this makes the minimum damping (with 0 signal into AGC and agcstate being 
tomwalters@0: % equal to the DetectFun value at zero, which may be zero) equal the nominal
tomwalters@0: 
tomwalters@0: for k = 1:Ntracks % track number (1 for mono, 2 for second channel)
tomwalters@0: %   pdampsmod(:,k) = pdamps.*min(1.5,(offset+agcfactor*...
tomwalters@0: %           (mean(agcstate')' + mean(agcstate(:,((k-1)*Nstages+1):k*Nstages)')')/2));
tomwalters@0:   pdampsmod(:,k) = pdamps.*(offset+agcfactor*...
tomwalters@0:           (mean(agcstate')' + mean(agcstate(:,((k-1)*Nstages+1):k*Nstages)')')/2);
tomwalters@0:   % the above hack weights the track AGC and the average equally
tomwalters@0:   % for mono is same as just ...ofset+agcfactor*sum(agcstates')'
tomwalters@0: end
tomwalters@0: 
tomwalters@0: %plot([detect, pdamps, pdampsmod, agcstate, sum(agcstate')'])
tomwalters@0: %drawnow