How can I animate the drawing of a figure 8 shape in a polar plot to confirm the path it takes?

Here is my code, where I am taking a figure 8 shape on a polar plot and rotating it around. I want to confirm the path that each figure 8 is drawn by animating it.

start = 0;
end_ = 2*pi;
disc = pi/16;
theta4 = 0:0.01:2*pi;
rho4 = sqrt(4*cos(2*theta4).*(sec(theta4).^4)); % figure 8 function
for i=0:31;
    interval = start+i*disc:0.01:end_+i*disc;
    %subplot(4,4,i+1)
    polarplot(interval,rho4)
    hold on
    pause(0.2)
end

Answer 1

[Steven Yeh]

Try this:

start = 0;
end_ = 2*pi;
disc = pi/16;
theta4 = 0:0.01:2*pi;
rho4 = sqrt(4*cos(2*theta4).*(sec(theta4).^4)); % figure 8 function

figure()
stepSize = 20;

for i=0:31
    interval = start+i*disc:0.01:end_+i*disc;        
    for k = 1:stepSize:length(rho4) 
        endPoint = min(k+stepSize, length(rho4)); % avoid array boundary exception
        polarplot(interval(k:endPoint), rho4(k:endPoint));
        hold on    
        pause(0.2)
    end
end

The stepSize variable used to set the speed of the animation

You can set the color in the outer i loop

[Omar Ahmed]

Thank you