fixations_n.m

function [fix, sac] = fixations_n(eyex, eyez, dispersion_th, duration_th_frames)

window = [1 duration_th_frames];
i = 1; % i is the fixations' index. first, second, third fixations
fdata = [];

while window(2) < length(eyex)
    D = ( max(eyex(window(1):window(2))) - min(eyex(window(1):window(2))) ) + ...
        ( max(eyez(window(1):window(2))) - min(eyez(window(1):window(2))) );

    if D <= dispersion_th
        
        while D <= dispersion_th && window(2) < length(eyex)
            window(2) = window(2) + 1;
            D = ( max(eyex(window(1):window(2))) - min(eyex(window(1):window(2))) ) + ...
                ( max(eyez(window(1):window(2))) - min(eyez(window(1):window(2))) );
        end
        
        if window(2) ~= length(eyex)
            window = [window(1), window(2) - 1];
        end
        
        fdata(i, 1:2) = [window(1) window(2)];
        fdata(i, 3) = (window(2) - window(1) + 1) / 130;
        fdata(i, 4:5) = [mean(eyex(window(1):window(2))), ...
            mean(eyez(window(1):window(2)))];
        
        i = i + 1;
        window = [window(2) + 1, window(2) + 13];
    else
        window = window + 1;
    end
end

fix = fdata;


sdata = [fdata(1:end - 1, 2), fdata(2:end, 1)];
dist = [eyex(sdata(:,1)) - eyex(sdata(:,2)), eyez(sdata(:,1)) - eyez(sdata(:,2))];
mag = sqrt(sum(dist .^2, 2));
theta = radtodeg(mag ./ 0.5);

sdata = [sdata, theta];

sac = sdata;

end