function voidbk = polygonfilmy(varargin)
% polygonfilm -  Aufbau und Abbau von regulaeren Dreiecken bis zu Achtecken
ntot=9; colvar = ['g','b','m','c','r'];
w = zeros(1,ntot);
r=9.8;
voidbk = 0;
%
t = (0:0.005:1)*2*pi;
xk = r*cos(t); yk = r*sin(t);
krhdl = plot(xk,yk,'k','LineWidth',2.5); hold on;
%
hdtx = text(-5.6,-2,'Polygon-Reigen', ...
    'FontUnits','points','FontSize',18 , ...
   'Fontweight','demi');
%
%axis equal;
%axis off;
k=0; 
wn = 0;
 w = [zeros(1,ntot-1) wn];
for wn = 0:0.005:1
  w(ntot) = wn ;
  if wn > 1/3
    w(ntot-1) = 1/3;
  end
  if wn > 2/3
    w(ntot-1) = 2/3;
    w(ntot-2) = 1/3;
  end
  if k>0
    delete(plhd)
  end
  k=1;
  x=r*sin(2*pi*w);
  y=r*cos(2*pi*w);
  plhd = plot(x,y,'r','LineWidth',4);
  pause(0.02)
  axis equal
end
%
pause(0.3)
for div =4:ntot-1
  ist = ntot-div+1;
  for wn=0:0.005:1/div
    w  = [zeros(1,ist-1) linspace(wn,1,div)];
      delete(plhd)
    x=r*sin(2*pi*w);
    y=r*cos(2*pi*w);
    plhd = plot(x,y,colvar(div-3),'LineWidth',4);
    pause(0.02)
  end
  pause(0.8)
end
%
pause(0.4)
for div =ntot-1:-1:4
  ist = ntot-div+1;
  for wn=1/div:-0.005:0
    w  = [zeros(1,ist-1) linspace(wn,1,div)];
      delete(plhd)
    x=r*sin(2*pi*w);
    y=r*cos(2*pi*w);
    plhd = plot(x,y,colvar(div-3),'LineWidth',4);
    pause(0.02)
  end
  pause(0.8)
end
%
w = [zeros(1,ntot-3) 1/3 2/3 1];
for wn = 1:-0.005:0
  w(ntot) = wn  ;
  if wn < 2/3
    w(ntot-2) = 0;
    w(ntot-1) = 1/3;
  end
  if wn < 1/3
    w(ntot-1) = 0;
  end
    delete(plhd)
  k=1;
  x=r*sin(2*pi*w);
  y=r*cos(2*pi*w);
  plhd = plot(x,y,'r','LineWidth',4);
  pause(0.02)
  axis equal
end
   delete(krhdl);
   delete(hdtx);
