Model for Simulating ECG and PPG Signals with Arrhythmia Episodes 1.3.1

function rr = simPAF_construct_real_RR(AFrhythm, rrLength)
% [] = simPAF_construct_real_RR() returns RR interval series, constructed
% using real RR intevals obtained from the MIT-BIH Normal Sinus Rhythm database
% (SR) and the Long Term Atrial Fibrillation database (AF). 
%
% Copyright (C) 2017  Andrius Petrenas
% Biomedical Engineering Institute, Kaunas University of Technology
%
% Available under the GNU General Public License version 3
% - please see the accompanying file named "LICENSE"
%
switch AFrhythm % If AFrhythm == 1 - AF, SR otherwise.
    case 0
        sigNum = randi([1 18]);  % Select randomly a single SR RR signal from 18 possible
        load('DATA_RR_SR_real');
        rrSR = DATArrSR(sigNum).rrSR;
        clear DATArrSR
            
        if rrLength > length(rrSR)   % Concatenate if RR series is shorter than the desired length
            nCycles = ceil(rrLength/length(rrSR));
            rr = [];
            for i = 1:nCycles
                rr = [rr rrSR];
            end
            rr = rr(1:rrLength);  
        else
            rrStart = randi([1 (length(rrSR)-rrLength)]); % Randomly select start position
            rr = rrSR(rrStart+1:rrStart+rrLength);
        end   
    case 1
        sigNum = randi([1 69]);  % Select randomly a single AF RR signal from 69 possible
        load('DATA_RR_AF_real');
        rrAF = DATArrAF(sigNum).rrAF;
        clear DATArrAF
            
        if rrLength > length(rrAF)   % Concatenate if RR series is shorter than the desired length
            nCycles = ceil(rrLength/length(rrAF));
            rr = [];
            rrAF
            for i = 1:nCycles
                rr = [rr rrAF];
            end
            rr = rr(1:rrLength);  
        else
            rrStart = randi([1 (length(rrAF)-rrLength)]); % Randomly select start position
            rr = rrAF(rrStart+1:rrStart+rrLength);
        end    
end

end