How to move circle frames to new locations?

Programming Help
1

Hi
I am a beginner to psychtoolbox and I need your help please.

1)For my current experiment, I have defined 8 possible locations that are distributed evenly around the fixation, Here is the codes representing this:

angle(1) = 270; % the position of the first item
step = 360/8;
for u = 2:8
angle(u) = angle(u-1) + step; % defining the circle points by the angles (first point is already fixed by first angle)
end

for j = 1:expinfo.nLocations
Xvalue = cosd(angle(j))*radius + x; %coordinate of the center of the object on the screen
Yvalue = sind(angle(j))*radius + y;
probe.circlevalue(1, j) = Xvalue- radi; % defining the points on the axes for each circle (adding and subtracting the radius to get 4 points per circle)
probe.circlevalue(2, j) = Yvalue- radi;
probe.circlevalue(3, j) = Xvalue+ radi;
probe.circlevalue(4, j) = Yvalue+ radi;
probe.colrs(1,j)=0;
probe.colrs (2,j)=0;
probe.colrs(3,j)= 0;
end

  1. Next, I drew randomly in every experimental trial 4 circles out of those 8 possible locations
    Here is the relevant code:
    LocationCandidates=randsample(1:8,4); % Sample 8 positions and pick only 4

Screen(‘FillRect’, w, background); % fills entire screen, effectively wiping it
Screen(‘FrameOval’, w, Colorsblack, probe.circlevalue(:,LocationCandidates), 2);
Screen (‘Flip’, w);
WaitSecs(3);
Screen(‘FrameOval’, w, Colorsblack, probe.circlevalue(:,LocationCandidates), 2);
Screen(‘Flip’, w, [], 1); % flips background screen to foreground

  1. The third step I need to do is to move those four circles simultaneously to randomly new locations (each circle takes any new location of the 8 predefined locations). I need to make the movement apparent that is from the old location to the new location. After several attempts I couldn’t accomplish it. Your help will be much appreciated