function [ppgsqi_numeric sqi_mean_30 annot_all]=calculate_ppgsqi(PPGann,Waveform,fs)
sqimatrix_all=zeros(length(PPGann),3);
sqi_mean_30=zeros(1,ceil(length(Waveform)/fs/30));
annot_all=[];
for j=1:length(PPGann)
annot_all(j)='Q';
end
% analysis PPG_SQI
windowlen=30*fs; % 30s window
template=[];
beat_i=1;
% loop every 30-sec
for j=1:ceil(length(Waveform)/windowlen)
try
databegin=(j-1)*windowlen+1;
dataend=min(length(Waveform),j*windowlen);
annf=find(PPGann<=dataend);
if length(annf)<=1
continue;
end
if length(annf)<length(PPGann)
annf(length(annf)+1)=annf(length(annf))+1;
end
annf=find(PPGann(annf)>=databegin);
if length(annf)<=1
continue;
end
anntime=PPGann(annf);
wave=Waveform(databegin:min(length(Waveform),max(dataend,anntime(length(anntime))+3*fs))); % prolong the data window an extra 3s
% set the anntime to be the 0 offset of the selected data
anntime=PPGann(annf)-databegin+1;
% PPG SQI analysis
[annot sqimatrix template valid] = PPG_SQI_buf(wave,anntime,template,30*fs,fs);
for k=1:length(annot)
annot_all(annf(k))=annot{k};
sqimatrix_all(annf(k),:)=sqimatrix(k,1:3); % 1:4
beat_i=beat_i+1;
end
sqi_mean_30(j)=mean(mean(sqimatrix(:,1:3)'));
catch
fprintf('PPGsqi error at segment %d ',j);
end
end
ppgsqi_numeric = round(mean(sqimatrix_all(:,1:3),2)');
end