How to plot a circle of some radius on a polar plot ?

eg. i want a small circle with origin as center of some radius...ON the POLAR plot

Answer 1

[Walter Roberson]

th = linspace(0,2*pi,50);
r = 10;
polar(th,r+zeros(size(th)))

[L K]

thanx :)

[Ron Beck]

I have used this script and it works (changed polar to polarPlot) but can't run it as a function. Any ideas?

Answer 2

[Gabriel Malagon Carvajal]

When is not center in the origen?

[Walter Roberson]

%need centres for demo purposes
xc = randn() * 5; yc = randn() * 5;

%the work
th = linspace(0,2*pi,50);
r = 10;
[x,y] = pol2cart(th,r);
[th1, r1] = cart2pol( x+xc, y+yc );
polar(th1, r1);