save n-Numbers of last interation from a loop

hello

i want to save always the last n (n between 1 and 6) interation of a loop.

i have a regulator which is read out in a loop. now i need always the last n inerations of the loop to calculate the desirerd condition.

 function ReglerButtonPushed(app, event)
          k=  app.KWertSlider.Value;
          bereich= app.BereichSlider.Value;
          speed= app.SpeedSlider.Value;
          fehlervek= zeros(6,1); 
          l
          app.stopRegler = false;
while app.stopRegler == false
 b = getBrightness(app,app.sensorPos(1),app.sensorPos(2));
 app.HelligkeitEditField.Value=b;
 fehler = b - 0.5; %actual mistake

i know how to save all mistakes - i just need the actually last n interations.

Answer 1

[Jan]

n         = 6;
fehlerVec = nan(1, n);
while app.stopRegler == false
   b = getBrightness(app,app.sensorPos(1),app.sensorPos(2));
   app.HelligkeitEditField.Value=b;
   fehler = b - 0.5; %actual mistake
   fehlerVec = [fehler(2:n), fehler];
end

Now fehlerVec contains the last n elements. There are more efficient solutions, but collecting these n values is most likely not the time-crticial part.