function f = myfun1(x,i)

        % 1 = practice1, 2=practice2, 3=test turning 30, 4=test turning 90, 5=test turning150
       %alpha = [210,120,30,60,75]; % no noise  %
      
        global PointingDirection       
        global building1 
        global building2 
        global building3 
        global building4   
        global building5 
       
            
        x = [x(1),x(2)];
        
        
        bearingA = getbearingA (x,building1,i); %get the bearing of the building relative to the estimated position and estiamted heading (remembered egocentric bearing the building). refer to the function of getbearingA in getbearingA.m
        bearingB = getbearingA (x,building2,i); %this remembered egocnetric bearing of the building should guide participants' pointing response
        bearingC = getbearingA (x,building3,i);
        bearingD = getbearingA (x,building4,i);
        bearingE = getbearingA (x,building5,i);
        
        
        
      
        errorA = (convertangleto180(bearingA - PointingDirection(1)))^2; %get the pointing error (from) refer to the function of convertangleto180 in convertangleto180.m
        errorB = (convertangleto180(bearingB - PointingDirection(2)))^2;
        errorC = (convertangleto180(bearingC - PointingDirection(3)))^2;
        errorD = (convertangleto180(bearingD - PointingDirection(4)))^2;
        errorE = (convertangleto180(bearingE - PointingDirection(5)))^2;

        f = sum(errorA)+sum(errorB)+sum(errorC)+sum(errorD)+sum(errorE);