greetings.rar_phi

function greetings(phi) % GREETINGS Seasonal holiday fractal. % GREETINGS(phi) generates a seasonal holiday fractal that depends % upon the parameter phi. The default value of phi is the golden ratio. % What happens for other values of phi? Try both simple fractions % and floating point approximations to irrational values. % Copyright 2014 Cleve Moler % Copyright 2014 The MathWorks, Inc. if nargin < 1 phi = (1+sqrt(5))/2; end clf shg set(gcf,'menu','none','numbertitle','off','name','Greetings', ... 'color','black') stop = uicontrol('style','toggle', ... 'units','normal','position',[.95 .95 .04 .04]); ax = [-60 120 -60 120]; sigma = .4; n = 100; z = 0; while get(stop,'value') == 0 & ... min(real(z)) > ax(1) & max(real(z)) < ax(2) & ... min(imag(z)) > ax(3) & max(imag(z)) < ax(4) z = cumsum(exp(i*(phi*pi*(0:n).^2+sigma))); plot(z,'g','linewidth',1) hold on plot(z(1:100:n+1),'r.','markersize',12); hold off axis(ax) axis off text(ax(1)+5,ax(3)+5,'Season''s Greetings','color','white',... 'fontsize',2*get(0,'defaulttextfontsize')) pause(1) n = n+100; end set(stop,'value',0,'string','X','callback','close(gcf)')