MATLAB: Please explain how this matlab code works works and what it does

MATLAB

Can anyone tell me how this code works?
clear
numofea=3;
subjectnum=10;
feanum=6;
featuredim=feanum*numofea;
windowsize=4;
numperfold=round(300-windowsize+1);
%datasize(subjectnum*numperfold,featuredim)=0;
alertfeasize(subjectnum*numperfold,featuredim)=0;
fatiguefeasize(subjectnum*numperfold,featuredim)=0;
subid0(subjectnum)=0;
y(subjectnum*2*numperfold)=0;
y(subjectnum*numperfold+1:end)=1;
foldidx(5*numperfold)=0;
%freqc=90;
filename={
% 'C:\Users\Adithya\Desktop\Eye tracking data\Li Rui Lin\eye_data_task_1 (5).mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Li Rui Lin\eye_data_task_4.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Yuan Liqiang\eye_data_task_1 (5).mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Yuan Liqiang\eye_data_task_4.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Adi\eye_data_task_1 (5).mat,
% 'C:\Users\Adithya\Desktop\Eye tracking data\Adi\eye_data_task_3.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Yu Lian\eye_data_task_1 (5).mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Yu Lian\eye_data_task_4.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 9\eye_data_task_1 (5).mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 9\eye_data_task_4.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 11\eye_data_task_2.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 11\eye_data_task_4.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 13\eye_data_task_3.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 13\eye_data_task_2.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 15\eye_data_task_1 (5).mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 15\eye_data_task_2.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 17\eye_data_task_1 (5).mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 17\eye_data_task_4.mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 19\eye_data_task_1 (5).mat',
% 'C:\Users\Adithya\Desktop\Eye tracking data\Subject 19\eye_data_task_2.mat'
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
'C:\Users\Adithya\Desktop\Eye tracking data\Li Rui Lin\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Li Rui Lin\eye_data_task_4.mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Yuan Liqiang\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Yuan Liqiang\eye_data_task_4.mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Adi\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Adi\eye_data_task_4.mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Yu Lian\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Yu Lian\eye_data_task_4.mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 9\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 9\eye_data_task_4.mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 11\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 11\eye_data_task_4.mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 13\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 13\eye_data_task_4.mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 15\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 15\eye_data_task_4.mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 17\eye_data_task_1 (5).mat'
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 17\eye_data_task_4.mat'
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 19\eye_data_task_1 (5).mat',
'C:\Users\Adithya\Desktop\Eye tracking data\Subject 19\eye_data_task_4.mat'
};
for tt=1:subjectnum
f1=filename{2*tt-1};
f2=filename{2*tt};
load(f1)
%%%%%%%%%%%%%%%%%%%%%
if tt>0
eyeData=eyeData.data;
end
%%%%%%%%%%%%%%%%%%%%%
% %%%%%%%%%%%
%
% cleanedeye=0;
% cleanedeye(size(eyeData,1),size(eyeData,2))=0;
%
% validsizenum=1;
% for i=1:size(eyeData,1)
% cv=eyeData(i,17:18);
% dv=cv<0;
% if ~any(dv(:))
% cleanedeye(validsizenum,:)=eyeData(i,:);
% validsizenum=validsizenum+1;
% end
% end
%
% eyeData=cleanedeye(1:(validsizenum-1),:);
% %%%%%%%%%
timeidx=eyeData(:,1);
I=find(timeidx>(timeidx(end)-5*60));
sampledtime=timeidx(I);
sampledtime=sampledtime-sampledtime(1);
% eyedata0=eyeData(I,3:4); %11:12
% eyedata0(:,3:4)=eyeData(I,11:12);
eyedata0=eyeData(I,14:16); %11:12
for j=1:numperfold
tidx=find(sampledtime>(j-1) & sampledtime<(j-1+windowsize));
for k=1:numofea
eye1=eyedata0(tidx,k);
ap=statistical_fea(eye1);
alertfeasize((tt-1)*numperfold+j, ((k-1)*feanum+1):k*feanum)=ap(1:feanum);
end
subid0((tt-1)*numperfold+j)=tt;
end
load(f2)
%%%%%%%%%%%%%%%%%%%%%
if tt>0
eyeData=eyeData.data;
end
%%%%%%%%%%%%%%%%%%%%%
% %%%%%%%%%%%%
%
% cleanedeye=0;
% cleanedeye(size(eyeData,1),size(eyeData,2))=0;
%
% validsizenum=1;
% for i=1:size(eyeData,1)
% cv=eyeData(i,17:18);
% dv=cv<0;
% if ~any(dv(:))
% cleanedeye(validsizenum,:)=eyeData(i,:);
% validsizenum=validsizenum+1;
% end
% end
%
% eyeData=cleanedeye(1:(validsizenum-1),:);
%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%
timeidx=eyeData(:,1);
I=find(timeidx>(timeidx(end)-5*60));
sampledtime=timeidx(I);
sampledtime=sampledtime-sampledtime(1);
% eyedata0=eyeData(I,3:4);%11:12
% eyedata0(:,3:4)=eyeData(I,11:12);
eyedata0=eyeData(I,14:16); %11:12
for j=1:numperfold
tidx=find(sampledtime>(j-1) & sampledtime<(j-1+windowsize));
for k=1:numofea
eye1=eyedata0(tidx,k);
ap=statistical_fea(eye1);
fatiguefeasize((tt-1)*numperfold+j, ((k-1)*feanum+1):k*feanum)=ap(1:feanum);
end
end
end
featuredata=cat(1,alertfeasize,fatiguefeasize);
subid=cat(2,subid0,subid0);
featuredata(isnan(featuredata))=0;
save('C:\Users\Adithya\Desktop\Eye tracking data\Results','featuredata','subid','y')
function fea=statistical_fea(data)
N1=size(data,1);
m=mean(data);
sd=std(data,1);
difference=diff(data);
s=sum(abs(difference));
absm1=1/(N1-1)*s;
sdabsm1=absm1/sd;
for n=3:1:N1
out1(n-2,1)=data(n,1);
end
s_temp=0;
for n1=1:1:(N1-2)
temp=out1(n1)-data(n1);
s_temp=s_temp+abs(temp);
end
absm2=1/(N1-2)*s_temp;
sdabsm2=absm2/sd;
%higu=hitguchiFD(data', 32);
fea=[m,sd,absm1,sdabsm1,absm2,sdabsm2];
end

Best Answer

I recommend contacting the person who gave you that code or the original author of the code and asking them for help understanding it. Asking focused questions about specific lines that you find particularly difficult rather than a blanket "please tell me what this does" might allow them to target their answers and so make them more useful.
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