DRAWLEAKCIRCLE - Create 'leaking' circles.

Contents

Description

Create a discrete disk (ie. with points on the regular lattice) with an approximated number of holes of approximated size.

Syntax

   DRAWLEAKCIRCLE(R, method, gap, ngap);
   [coord, A] = DRAWLEAKCIRCLE(R, method, gap, ngap, M, disp);

Inputs

R : radius of the circle.

method : string defining the method used for creating holes in the set of lattice points sampled on the disk; it is either:

gap : size of the holes (in number of pixels/points).

ngap : desired number of holes.

M : (optional) half-size of the output image A displaying the circle; M should be >(R+1); default: M=R+1.

disp : (optional) flag for drawing (discrete) lines; default: disp=false.

Outputs

coord : vector (N,2) of the (X,Y)-coordinates of the N sampled points.

A : output logical image of size (2*M+1,2*M+1) with the 'leaking' circle displayed (set to true for points whose coordinates are given by coord).

See also

Ressembles: DRAWCIRCLE, DRAWGESTALT. Requires: DRAWLEAKCIRCLE_BASE.

Function implementation

function varargout = drawleakcircle(R, method, gap, ngap, M, disp)

setting/checking parameters

error(nargchk(4, 6, nargin, 'struct'));
error(nargoutchk(0, 2, nargout, 'struct'));

% set default
if nargin<6
    if nargout==0,  disp = true;
    else            disp = false;     end
    if nargin<5 || isempty(M)
        M = R+1;
    elseif M<=R
        warning('drawleakcircle:inputwarning', ...
            'too small output image - enlarged domain');
        M = R+1;
    end

end

main computation

[coord, A] = drawleakcircle_base(R, method, gap, ngap, M);

display

if disp
    figure, plot(coord(:,1), coord(:,2), 'k.');
    center = [M M];
    axis([center(1)-1.1*R center(1)+1.1*R center(2)-1.1*R center(2)+1.1*R])
    axis equal
    % figure, imagesc(A), colormap gray, axis image off
end

if nargout>=1,  varargout{1} = coord;
    if nargout==2,  varargout{2} = A;  end
end

end % end of drawleakcircle