Code to draw multiple circles that do not overlap

In Matlab, I try to draw circles randomly as shown in the following figure.

The current situation is drawn like this and I am in trouble because I have no idea how to make it a circle.

%the code of the current situation 
t = linspace(0,2*pi,100);
figure
cx = 200 + (rand(20, 1) .* 1000); %center of the circle
cy = 300 + (rand(20, 1) .* 1000); %center
r = 2; %radius
plot(r*sin(t)+cx,r*cos(t)+cy)
y = r*cos(t)+cy
x = r*sin(t)+cx
for i =0:20
  fill(x,y,'k')  
  %fill(r*sin(t)+cx,r*cos(t)+cy, 'k')
  r = r+1;    
end
i=i+1;
axis([0,1200,0,1200])
axis square

Answer 1

[michio]

When the inputs are matrices, the functions draw columns of Y versus columns of X. So could you try changing

 fill(x,y,'k')

to

 fill(x',y','k')

I just transposed the matrices, x and y. The radius might need to be a bigger number though.

P.S. If you perfer, posting questions in Japanese is also always welcome :)

[michio]

I forgot to mention but you do not need the for loop.

for i =0:20
  fill(x,y,'k') 
end

Simply calling

 fill(x',y','k');

would work.

Answer 2

[H Y]

Thank you. It has worked. I would appreciate if you could give me advice regarding the another question which I have posted. There is no answer from anyone, and what should I do to improve the situation of it?