Drawing Circles in Matlab

drawCircles.m

function drawCircles(center,radius,NOP,style)
%------------------------------------------------------------------------------
% CIRCLE(CENTER,RADIUS,NOP,STYLE)
% This routine draws a circle with center defined as
% a vector CENTER, radius as a scaler RADIS. NOP is
% the number of points on the circle. As to STYLE,
% use it the same way as you use the rountine PLOT.
% Since the handle of the object is returned, you
% use routine SET to get the best result.
%
%   Usage Examples,
%
%   circle([1,3],3,1000,':');
%   circle([2,4],2,1000,'--');
%
%   Zhenhai Wang <[email protected]>
%   Version 1.00
%   December, 2002
%
%   Modified by James Church
%------------------------------------------------------------------------------

if size(center, 1) ~= size(radius, 1)
        error('Length of center and radius should be equal.')
    end

    if nargin == 2
        NOP = 1000;
    end

    if nargin < 2
        error('Please see help for INPUT DATA.');
    elseif (nargin < 3)
        style='b-';
    end;

    n = length(radius);
    THETA=linspace(0,2*pi,NOP);
    hold on;

    for i = 1:n
        RHO=ones(1,NOP)*radius(i);
        [X,Y] = pol2cart(THETA,RHO);
        X=X+center(i, 1);
        Y=Y+center(i, 2);
        plot(X,Y,style);
    end
end

You can draw circles using the rectangle function; there is no need for plotting:

https://mathworks.com/help/matlab/ref/rectangle.html#busqhee-1