function drawellipse (z, a, b, alpha, pat, OPTIONS)%DRAWELLIPSE	Draw ellipse%%	drawellipse (z, a, b, alpha, pat{'-'}, OPTIONS{[]})%	draws ellipse into current figure.%%	z, a, b, alpha: parameters of ellipse%	pat: pattern to be used  if (nargin < 6), OPTIONS = [2]; end;  if (nargin < 5), pat = '-'; end;  s = sin(alpha); c = cos(alpha);  Q =[c -s; s c];  theta = [0:0.02:2*pi];  u = diag(z)*ones(2,length(theta)) + ...      Q*[a*cos(theta); b*sin(theta)];  plot(u(1,:),u(2,:), pat);  if (find(OPTIONS==2) == []),    plot(z(1),z(2),'+');  end  if (find(OPTIONS==1) ~= []),    if (a < b),       alpha = alpha + pi/2;      tmp = a; a = b; b = tmp;    end    alpha = alpha - pi*floor(alpha/pi);    at = text(z(1),z(2),'  a');    at2 = text(z(1)+1,z(2),'  a');    set(at2,'Visible','off');    ext = get(at, 'Extent');    xa2  = ext(1);    set(at, 'FontName', 'Symbol');    ext = get(at, 'Extent');    wa  = ext(3);    xa  = ext(1);    bt  = text(z(1)+(xa2-xa)/wa,z(2),sprintf(' = %1.4f',alpha));  end end % drawellipse