% fadensternfilm.m - Animation eines Spiral- Fadensternes
function voidbk = fadensternfilm3(varargin)
voidbk = 0;
% pythspira pythagoreische Schnecke 
%  Spiralform aus lauter rechtwinkligen Dreiecken
ntot=70; n=1:ntot; r = sqrt(n); fc = 1.3; 
dw = atan2(ones(1,ntot),r);  s = 0;
for k=1:ntot; w(k) = s; s = s + dw(k); end
dw; w;
vx = fc*r.*cos(w); vy = fc* r.*sin(w); 
hdx(1) = plot([vx(1) 0], [vy(1) 0],'b');
  pause(0.05)
hold on
axis([-10 10 -10 10]); axis square; axis off
% Schleife
for k=2:ntot
  hdx(k) =  plot([vx(k) 0], [vy(k) 0],'b');
  pause(0.05)
end  
for k=1:ntot
  delete(hdx(k));
  pause(0.05)
end

