Condition inside animation loop

if i have animation part inside loop like below

%% animation part 
while( distanceToGoal > goalRadius )

    [v, omega] = step(controller, robot.CurrentPose);
    drive(robot, v, omega)
    robotCurrentLocation = robot.CurrentPose(1:2)
    distanceToGoal = norm(robotCurrentLocation - robotGoal); 
end

during execute the above code, the simulation give me the current position of robot.

i would like to put the below code

 for i = 1 : 5
        rN = rand;
    pause(2)
     disp(['rN = ' num2str(rN)])
     if rN > 0.8
     end
   end

inside the animation part, so each two seconde it will give me different random values,

if rN > 0.8 i need stop the robot

any help please