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• Circled bird 1

on 19 Nov 2023
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drawframe(48);
function drawframe(f)
% function from [Hamid Naderi Yeganeh] : https://www.ams.org/publicoutreach/math-imagery/yeganeh
K=1:min(260*f,9830);
t=linspace(0,2*pi,200);
X=@(k) (sin(pi.*k./2e4)).^12.*(cos(31.*pi.*k./1e4).^16.*sin(6.*pi.*k./1e4)./2+sin(31.*pi.*k./1e4).^20./6)...
+3.*k./2e4+cos(31.*pi.*k./1e4).^6.*sin(pi./2.*(k./1e4-1).^7-pi./5);
Y=@(k) -9./4.*cos(31.*pi.*k./1e4).^6.*cos(pi./2.*(k./1e4-1).^7-pi./5).*(2./3+(sin(pi.*k./2e4).*sin(3.*pi.*k./2e4)).^6)...
+3./4.*cos(3.*pi.*(k-1e4)./1e5).^10.*cos(9.*pi.*(k-1e4)./1e5).^10.*cos(36.*pi.*(k-1e4)./1e5).^14+7./10.*((k-1e4)./1e4).^2;
R=@(k) sin(pi.*k./2e4).^10.*(1./4.*cos(31.*pi.*k./1e4+25.*pi./32).^20+1./20.*cos(31.*pi.*k./1e4).^2)+1./30.*(3./2-cos(62.*pi.*k./1e4).^2);
CX=[X(K')+cos(t).*R(K'),K'.*nan]';
CY=[Y(K')+sin(t).*R(K'),K'.*nan]';
plot(CX(:),CY(:),'Color',[0,0,0,.05]);
set(gca,'DataAspectRatio',[1,1,1],'XColor','none','YColor','none','XLim',[-1 2],'YLim',[-3 2]);
end