wolffd@0: function h = draw_circle(x, r, outline_color, fill_color)
wolffd@0: % draw filled circles at centers x with radii r.
wolffd@0: % x is a matrix of columns.  r is a row vector.
wolffd@0: 
wolffd@0: n = 40;					% resolution
wolffd@0: radians = [0:(2*pi)/(n-1):2*pi];
wolffd@0: unitC = [sin(radians); cos(radians)];
wolffd@0: 
wolffd@0: % extend r if necessary
wolffd@0: if length(r) < cols(x)
wolffd@0:   r = [r repmat(r(length(r)), 1, cols(x)-length(r))];
wolffd@0: end
wolffd@0: 
wolffd@0: h = [];
wolffd@0: % hold is needed for fill()
wolffd@0: held = ishold;
wolffd@0: hold on
wolffd@0: for i=1:cols(x)
wolffd@0:   y = unitC*r(i) + repmat(x(:, i), 1, n);
wolffd@0:   if nargin < 4
wolffd@0:     h = [h line(y(1,:), y(2,:), 'Color', outline_color)];
wolffd@0:   else
wolffd@0:     h = [h fill(y(1,:), y(2,:), fill_color, 'EdgeColor', outline_color)];
wolffd@0:   end
wolffd@0: end
wolffd@0: if ~held
wolffd@0:   hold off
wolffd@0: end